Atom Interview Questions & Answers

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Atom Interview Questions & Answers

This is the first time to attend the interview? Finding another job can be so cumbersome that it can turn into job itself. Prepare well for with the latest information at wisdom jobs online portal. An atom is a smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas and plasma is composed of neutral or ionized atoms. Atoms together join to form molecules which in turn form most of the objects around you. Various leading research centres are offering creative and rewarding career opportunities to young qualified candidates who like challenges in frontline areas of science and technology. Ample aspects are available for pursuing innovative research in physics, chemistry, nuclear science etc. You can work as scientists and engineers, technical officers etc. Avail the opportunity by looking into atom job interview questions and answers below.

Atom Interview Questions

Atom Interview Questions
    1. Question 1. What Is An Atom? What Are Atoms Made Of?

      Answer :

      Atoms are the basic building blocks of ordinary matter. Atoms can join together to form molecules, which in turn form most of the objects around you.

      Atoms are composed of particles called protons, electrons and neutrons. Protons carry a positive electrical charge, electrons carry a negative electrical charge and neutrons carry no electrical charge at all. The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus. A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons.

      Protons and neutrons are both composed of other particles called quarks and gluons. Protons contain two 'up' quarks and one 'down' quark while neutrons contain one 'up' quark and two 'down' quarks. The gluons are responsible for binding the quarks to one another.

    2. Question 2. What Is One Example Of Indirect Evidence That Scientists Use To Study An Atom?

      Answer :

      Pretty much everything we know about atoms is indirect evidence. One can't really see atoms. We do see enough of their effects that we can, with confidence, describe the nature of atoms.

      Here at Jefferson Lab we have quite a few instruments to measure the properties and behavior of atoms. We use a few simple tricks to measure atoms. The most common method is to shoot the atoms through an easy-to-ionize gas or liquid.

      Argon is the most common that we use. As the atoms or even pieces of atoms fly through the gas electrons are stripped off of them and are left behind. We drift those loose electrons to a collection device, a wire or panel, and measure the charge. It is a little more complex than that, but it works well enough that we get consistent results.

      It's like putting together a puzzle that's missing some pieces. If you get enough pieces in the right place you can tell what the picture is even though it still has holes.

    3. Question 3. What Is An Element? How Many Elements Are There?

      Answer :

      An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron. If you change the number of protons an atom has, you change the type of element it is.

      If you had very, very good eyes and could look at the atoms in a sample of hydrogen, you would notice that most of the hydrogen atoms would have no neutrons, some of them would have one neutron and a few of them would have two neutrons. These different versions of hydrogen are called isotopes. All isotopes of a particular element have the same number of protons, but have a different number of neutrons. If you change the number of neutrons an atom has, you make an isotope of that element.

      Currently, scientists know of 118 different elements. Some, like gold, silver, copper and carbon, have been known for thousands of years. Others, such as meitnerium, darmstadtium and ununquadium, have only recently been created by scientists. All known elements are arranged on a chart called the Periodic Table of Elements.

    4. Question 4. What Is The Simplest Way Of Explaining What Atoms, Elements, Compounds And Mixtures Are?

      Answer :

      Atoms are the smallest bits of ordinary matter and are made from particles called protons (which carry a positive electrical charge), neutrons (which carry no electrical charge) and electrons (which carry a negative electrical charge). The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus. A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons.

      An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing just one proton and one electron. If you had very, very good eyes and could look at the atoms in a sample of hydrogen, you would notice that most of the atoms have no neutrons, some of them have one neutron and a few of them have two neutrons. These different versions of hydrogen are called isotopes. All isotopes of a particular element have the same number of protons, but can have different numbers of neutrons. If you change the number of protons an atom has, you change the type of element it is. If you change the number of neutrons an atom has, you make an isotope of that element. All known elements are arranged on a chart called the Periodic Table of Elements.

      A compound is a substance made from two or more different elements that have been chemically joined. Some examples of compounds are water (H2O), table salt (NaCl), table sugar (C12H22O11) and chalk (CaCO3).

      A mixture is a substance made by combining two or more different materials in such a way that no chemical reaction occurs. A mixture can usually be separated back into its original components. Some examples of mixtures are a tossed salad, salt water and a mixed bag of M&M's candy.

    5. Question 5. What Is A Mixture?

      Answer :

      A mixture is a substance made by combining two or more different materials in such a way that no chemical reaction occurs. A mixture can usually be separated back into its original components. Some examples of mixtures are a tossed salad, salt water and a mixed bag of M&M's candy.

    6. Question 6. What Is The Difference Between A Compound And A Molecule?

      Answer :

      A molecule is formed when two or more atoms join together chemically. A compound is a molecule that contains at least two different elements. All compounds are molecules but not all molecules are compounds.

      Molecular hydrogen (H2), molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element. Water (H2O), carbon dioxide (CO2) and methane (CH4) are compounds because each is made from more than one element. The smallest bit of each of these substances would be referred to as a molecule.

      For example, a single molecule of molecular hydrogen is made from two atoms of hydrogen while a single molecule of water is made from two atoms of hydrogen and one atom of oxygen.

    7. Question 7. I Am Not Clear On What A Molecule Is. If Water Is A Molecule, Is It Also A Compound Because The Hydrogen And Oxygen Have Been Chemically Combined? If So, How Do You Determine Whether A Substance Is A Compound Or A Molecule?

      Answer :

      1. A molecule is what you get when any atoms join together.
      2. A compound is what you get when atoms of two or more different elements join together.
      3. All compounds are molecules, but not all molecules are compounds.
      4. Water is a molecule because it is made from atoms that have been chemically combined. It is also a compound because the atoms that make water are not all the same - some are oxygen and some are hydrogen.
      5. Oxygen in the atmosphere is a molecule because it is made from two atoms of oxygen. It is not a compound because it is made from atoms of only one element - oxygen. This type of molecule is called a diatomic molecule, a molecule made from two atoms of the same type.

    8. Question 8. What Is The Biggest Atom? The Smallest Atom?

      Answer :

      If by "biggest" and "smallest", you mean mass (which is a measure of how much matter is there), then the smallest is the hydrogen atom with one proton and one electron. Since electrons are about 2000 times less massive than protons (and neutrons), then the mass of an atom is mostly from the protons and neutrons. So the hydrogen atom "weighs" in as ONE.

      As you add more protons and neutrons, the mass increases. However, for very massive atoms, the force holding them together becomes unstable and they tend to break apart (a phenomenon known as radioactive decay). Very massive atoms such as nobelium and lawrencium have lifetimes of only a few seconds.

      On the other hand, if you are speaking of size, then atoms are all about the same size whether it's a hydrogen atom (the simplest and least massive with one proton and one electron) or a lead atom (with 82 protons, 82 electrons and 125 neutrons).

      Atoms are composed of a nucleus (where the positively charged protons and uncharged neutrons reside) surrounded by a cloud of orbiting negatively charged electrons. An atom is about 10-8 centimeters in size (meaning that 100 million of them would fit side-by-side within one centimeter). The tightly packed nucleus is 100,000 times smaller than the electron cloud.

      You might think that as you add more protons (and thus more positive charge), the electrons would be attracted more strongly to the inner nucleus and hence the atom would shrink. In reality the electrons tend to screen each other somewhat from the inner positive charge and so the size stays about the same.

    9. Question 9. How Do Atoms Form?

      Answer :

      The current view is that atoms are made up of protons and neutrons (which in turn are made up of quarks and gluons) and electrons. The protons and neutrons are at the central core called the nucleus, and the electrons revolve around it, being held in orbit by the electromagnetic force between the negatively charged electrons and the positively charged protons in the central nucleus.

      It is very much like the solar system with the sun at the center and the planets revolving around it. They were formed right after the "Big Bang" when our known universe originated from pure energy some billions of years ago. The energy was converted to the elementary particles (quarks, gluons, leptons etc...) from which protons and neutrons were formed. From these, atoms of different elements were produced.

    10. Question 10. Does Gravity Affect Atoms?

      Answer :

      Gravity affects atoms the same way it affects all other matter. Every atom creates its own gravitational field which attracts all other matter in the universe. If you put a lot of atoms together, like in a planet or a star, all of the little gravitational fields add together, creating a much stronger pull.

      If you could hold an atom in your hand and drop it, it would fall to the ground, just like a book or a brick. In fact, if you could remove all the air from a room and drop an atom in a vacuum, it would fall to the ground at exactly the same rate as a book or a brick would. After all, a book or a brick is nothing more than a collection of atoms.

    11. Question 11. Can You Crush Atoms?

      Answer :

      Not normally, but there are certain types of stars, called neutron stars, that are made from 'crushed' atoms. The gravitational field is high enough in a neutron star that the electrons around an atom are forced to combine with the protons in the nucleus, creating neutrons. Imagine the sun squeezed into a sphere a few miles across. A teaspoon full of neutron star material would weigh several tons.

      Also, black holes are the ultimate example of crushed atoms. According to the math, the matter which makes a black hole takes up no space at all.

    12. Question 12. Is There An Atom That Does Not Have Neutrons?

      Answer :

      There is only one stable atom that does not have neutrons. It is an isotope of the element hydrogen called protium. Protium, which contains a single proton and a single electron, is the simplest atom. All other stable atoms contain some number of neutrons.

    13. Question 13. What Kind Of Charge Does A Proton Have? And What Kind Of Charge Does A Neutron Have?

      Answer :

      A proton has positive charge of 1, that is, equal but opposite to the charge of an electron. A neutron, like the name implies, is neutral with no net charge.

      The charge is believed to be from the charge of the quarks that make up the nucleons (protons and neutrons). A proton is made of two Up quarks, with 2/3 positive charge each and one Down Quark with a negative 1/3 charge (2/3 + 2/3 + -1/3 = 1). A neutron is made up of two Down quarks with a negative 1/3 charge each and one Up quark with a positive 2/3 charge. (-1/3 + -1/3 + 2/3 = 0).

    14. Question 14. Why Do Protons And Neutrons Stay Together In The Nucleus?

      Answer :

      The nucleus of an atom is held together by the strong nuclear force that binds together protons and neutrons. Although the strong nuclear force is the strongest of the four fundamental forces, it acts only over very short - typically nuclear - distances. It binds together the protons and neutrons in the nucleus. It also holds together the quarks that make up those protons and neutrons and the other hadrons.

    15. Question 15. How Many Times Bigger Is A Proton Than An Electron?

      Answer :

      It depends on what you mean by bigger. A proton is about 1835 times more massive than an electron. If you are asking about their physical dimensions - no one knows. Scientists currently do not know how small electrons are. They are smaller than we can currently measure and may not have a size at all!

    16. Question 16. Why Are Electrons So Far Away From The Nucleus Of An Atom?

      Answer :

      Electrons are indeed far away from the nucleus! If we could magnify the simplest hydrogen atom so that its nucleus (a proton) were the size of a basketball, then its lone electron would be found about 2 miles away. All of the space in between the electron and the basketball-size nucleus is empty!

      But why the electron is so far from the nucleus is no more mysterious than some of your everyday experiences. Imagine that you tied a baseball to the end of a long rubber band. You hold the other end of the rubber band in your hand and start swinging the ball around in a circle. The faster the ball goes, the more the rubber band stretches and the farther away is the baseball. In an atom, an electron is attracted to the nucleus by the "electromagnetic force", similar to your rubber band.

      Like your baseball, the faster the electron goes, the farther away from the nucleus it is. The electrons in an atom are moving pretty fast, so they are far away from the nucleus. If you dig a little deeper into the problem you will discover some differences, though. Unlike the rubber band which pulls harder on the ball as it is stretched more and more, the electromagnetic force gets WEAKER as the electron and nucleus get farther apart. This does not change the basic idea. It's as if the rubber band never breaks, but just stretches more easily the longer it becomes.

      Another difference is that nature only allows atomic electrons to have certain amounts of energy - they can only go at certain speeds. The science that explains this is called "quantum mechanics". The SLOWEST allowed speed is the one that puts that electron about 2 miles away from the basketball-sized nucleus! It could have MORE energy and be even farther away!

    17. Question 17. If Atoms Are 99.999999999999% Empty Space Then Why Don't Things Pass Right Through Them?

      Answer :

      Things don't fall through other things because they are levitating on an electrostatic field! I am not kidding! When you sit on a chair, you are not really touching it. You see, every atom is surrounded by a shell of electrons.

      This electron cloud presents a rather negative face to the world. Remember that like charges repel each other. When two atoms approach each other, their electron shells push back at each other, despite the fact that each atom's net charge is 0. This is a very useful feature of nature. It makes our lives a lot easier.

    18. Question 18. How Fast Do Electrons Move?

      Answer :

      As fast as you can get them going! Well not quite. One of the facts of life discovered in the 20th century is that the speed of light (300,000 kilometers per second) is the ultimate speed limit. As you add energy to the electron, it will go faster, but as you get it to go close to the speed of light, you find that you have to add even more energy just to bump it a bit faster.

      For example, with just over 220,000 eV (which stands for a convenient unit of energy called the "electron-volt"), you can get the electron up to 90% of the speed of light. But to get it to 99.9% (just another 9.9%), you need a total of over 11 million eV! One way of looking at this is that the electron gets "heavier" (more massive) as it goes ever faster. So it's harder to push it faster.

      At Jefferson Lab, a typical energy for the electrons in the beam is 4 GeV which is 4 billion eV. That means the electron is traveling at 99.9999992% of the speed of light. Close but still not 100%.

      You may wonder how fast the electrons are whizzing around in the atoms around you.A good example (and the most simple to calculate) is the hydrogen atom which is in all our water. A calculation shows that the electron is traveling at about 2,200 kilometers per second.

      That's less than 1% of the speed of light, but it's fast enough to get it around the Earth in just over 18 seconds. Read up on what happens when nothing can go faster than the speed of light.

    19. Question 19. What Do We Use To Measure Mass?

      Answer :

      The difference between mass and weight causes a lot of confusion amongst a lot of people. Put simply, weight is a measure of gravity's effect on something. Mass is the amount of matter in an object. Move to a different planet and an object's weight will change, but its mass will be the same.

      There are a couple of ways to measure mass. The most common method is to use a balance. Hey, wait a minute! (you should be saying) People weigh stuff all the time with a balance! Think about it. If you go to a different planet, the balance weights change by the same factor as the object you are measuring. Your mass measured with a balance would be the same on the moon as it is on Earth. There are a couple of other neat tricks, but they only really work perfectly in no-gravity, no-friction environments.

      For example imagine a big rock floating in space. Give it a slap with a calibrated hand so you know exactly how much energy you gave it. Now measure how fast the rock is moving. That new speed is proportional to its mass. In space you weigh nothing, but your mass is the same, so a space bully can still shove the 98 pound weakling even though they both weigh 0 pounds.

    20. Question 20. If Everything Around Us Is Matter, What About Germs?

      Answer :

      Yes, germs are matter. The definition of matter is something that has mass and occupies space. Germs certainly meet that criteria. Of course, germs are tiny and impossible to see without some tool to amplify our senses, BUT they are huge compared to the atoms that make up those germs. Those atoms are also matter and are even smaller and harder to see than germs.

      About the only place you can be where you aren't completely surrounded by matter is in space and even there, there is some matter, just not nearly as much as here on Earth.

      You wouldn't really like it there though because without all that nice matter (remember air is matter also) pushing on your body, you would be "uncomfortable". Ok, you'd pop, but I would call that being pretty uncomfortable.

    21. Question 21. Why Is Matter Not Being Created At The Present Time, Nor Being Destroyed?

      Answer :

      Matter is being created and destroyed now. For example, a high energy X-ray can collide with the nucleus of an atom and disappear and two particles, an electron and an anti-electron (a.k.a. positron), will appear in its place. So extra matter is being produced from no matter.

      The important thing is that the amount of total energy stays the same, but the energy can change its form from electromagnetic radiation (the X-ray) to matter (the electron and positron). Also, an electron and positron can collide with and annihilate each other, producing X-rays.

    22. Question 22. What Is Plasma?

      Answer :

      Plasma is the fourth state of matter. Many places teach that there are three states of matter; solid, liquid and gas, but there are actually four. The fourth is plasma. To put it very simply, a plasma is an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist. The funny thing about that is, that as far as we know, plasmas are the most common state of matter in the universe. They are even common here on earth.

      A plasma is a gas that has been energized to the point that some of the electrons break free from, but travel with, their nucleus. Gases can become plasmas in several ways, but all include pumping the gas with energy. A spark in a gas will create a plasma. A hot gas passing through a big spark will turn the gas stream into a plasma that can be useful. Plasma torches like that are used in industry to cut metals.

      The biggest chunk of plasma you will see is that dear friend to all of us, the sun. The sun's enormous heat rips electrons off the hydrogen and helium molecules that make up the sun. Essentially, the sun, like most stars, is a great big ball of plasma.

    23. Question 23. Could There Be Anything Smaller Inside Of An Electron Or Inside Of A Neutron Or A Proton?

      Answer :

      Yes, there could. Right now, our best evidence says that there are particles inside of neutrons and protons. Scientists call these particles quarks. Our best evidence also shows us that there is nothing inside of an electron except the electron itself.

    24. Question 24. How Many Quarks Are In A Proton? How Many Quarks Are In A Neutron?

      Answer :

      Protons and neutrons each contain three quarks. A proton is composed of two 'Up' quarks and one 'Down' quark while neutrons are composed of one 'Up' quark and two 'Down' quarks.

    25. Question 25. What Is The Charge Of An Up Quark And The Charge Of A Down Quark? How Many Quarks Make Up A Proton And A Neutron?

      Answer :

      Protons and neutrons are each composed of three quarks. Protons are made up of two 'up' quarks and one 'down' quark while neutrons are made up of two 'down' quarks and one 'up' quark.

      Quarks carry fractional electrical charges. An 'up' quark has a charge of +2/3 and a 'down' quark has a charge of -1/3. Is this consistent with what we know about protons and neutrons? Remember that protons carry an electrical charge of +1 while neutrons carry no electrical charge. We said earlier that a proton has two 'up' quarks and one 'down' quark, so it has a total charge of (+2/3) + (+2/3) + (-1/3) = +1.

      We also said that a neutron has two 'down' quarks and one 'up' quark, so it has a total charge of (-1/3) + (-1/3) + (+ 2/3) = 0. Happily, both the proton and the neutron 'end up' with the charge they should have.

    26. Question 26. What Is A Vacuum? Is It Matter?

      Answer :

      A vacuum, to us, is a space with no matter in it. As a practical matter though, it's really a space with very little matter in it. You might already know that it's REALLY hard to get all the matter out of any space.

      Believe it or not, vacuums are very important and are becoming more useful every day. There is actually a whole branch of science dedicated to creating and studying vacuums.

      Many modern devices (like the integrated circuit chips that make everything from cars to computers work), have to be fabricated in a vacuum. Jefferson Lab uses vacuums for thermal insulation. A lot of our equipment will only work at extremely cold temperatures.

      We operate at 2 degrees above the lowest possible temperature in the universe - you bet we're paying attention to insulation! If you could insulate your home with the same insulating vacuum that we use for our accelerator then you wouldn't need a furnace at all!

      Even outer space, which is considered a vacuum and has less matter in it than anything mankind can reproduce, still has some atoms bouncing around.

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