Do all atoms have no electric charge?

Its subatomic particles carry no electrical charge.

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The positively charged protons cancel out the negatively charged electrons.

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The positively charged protons cancel out the negatively charged neutrons.

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Solution

The correct option is BThe positively charged protons cancel out the negatively charged electrons.The explanation for the correct option:An atom is the smallest unit of matter that encompasses all the chemical properties of the element. An atom is composed of three subatomic particles known as electron, proton and neutron which are responsible for the entire mass and charge of the atom.(B) The positively charged protons cancel out the negatively charged electrons: The positively charged protons are found inside the nucleus, which balances negatively charged electrons rotating in the circular path called the orbit. Hence, the atom remains neutral.The explanation for the incorrect options:(A) Its subatomic particles carry no electrical charge: Subatomic particles inside the atom named as protons and electrons carry positive and negative charge respectively.(C) The positively charged protons cancel out the negatively charged neutrons: Subatomic particle neutrons are present in the nucleus and do not carry any atomic charge.Hence, option (B) is correct, the positively charged protons cancel out the negatively charged electrons.

Supplementary Reading - Lecture 22

Today we begin with the discussion of electricity. Consider the following:

• When you walk on a rug on a dry day, and then insert your key into a door lock, a spark will often jump between your key and the metal of the lock. What is a spark made of?
• What is lightning, and is it the same kind of thing as the spark mentioned above?
• Why does your hair stick to the comb on a dry day?

The effects of electricity have long been known, and it is interesting to study the historical development of the subject. However, it is simplest to start with what has been learned up to the present. Here are the facts:

• All matter is made of atoms. As we will discuss in physics 110b, atoms are all made of the same building blocks. They have a tiny nucleus about 10-13 meters in diameter. The atom's nucleus contains two kinds of particles: neutrons and protons. We say that protons have charge of +1 and that neutrons have no charge. Surrounding the nucleus are electrons which spread over a region which is about 100000 times as great in diameter than the diameter of the nucleus. So the electrons extend out to about 10-8 meters. Electrons have electric charge of -1 and the number of electrons in an atom is equal to the number of protons. Hydrogen is the simplest atom with one proton and one electron. Helium has two protons and two neutrons, and, therefore, two electrons.The most common form of Carbon has 6 protons, 6 neutrons and 6 electrons. Nitrogen has 7 protons, 7 neutrons and 7 electrons. Heavier atoms tend to have more neutrons than protons, but the number of electrons in an atom is always equal to the number of protons. So an atom as a whole is electrically neutral.
• When one or more electrons is stripped away from an atom, it becomes positively charged. Some atoms can attract additional electrons so they become negatively charged. Atoms which are not electrically neutral are called ions.
• One can collect electric charge by transferring electrons. Materials with an excess of electrons are negatively charged. Those with a deficiency of electrons are positively charged.
• Simple experiments can be done with an electroscope. See Figures 19.7 and 19.8. The foils in the electroscope move apart when they receive an excess of electrons or when they lose electrons and become positively charged.
• Objects with the same sign of charge repel each other and objects with opposite sign of charge attract. The mathematical expression for this is called Coulomb's law and is given by:
  Force = constant Q(1) x Q(2) / r2,
  where Q(1) is the charge on object 1, in units of Coulombs,
  Q(2) is the charge on object 2, also in Coulombs, and r is the
  distance between the objects in meters. The force is in Newtons when the constant is appropriately chosen.

Everything is Made of Atoms

Famed physicist Richard Feynman once said that the single most important thing learned from scientific studies is that everything is made of atoms. Knowing about atoms helps us understand electricity because we find that atoms are made of tiny particles with electric charge, both positive charge and negative charge. We then learn that charges have the property that same sign repel each other while charges of opposite sign attract. See the website Properties of Matter for an animated introduction to the subject.

Electricity in Our Everyday World

Electric forces hold together atoms and produce chemical reactions. We depend on the flow of electric charges, or electric currents, to make all kinds of appliances work in our modern world. We witness the power of electricity in lightning bolts. See this website on Electricity and Magnetism for an elementary introduction.

Negative charges are removed from a piece of fur and deposited on to a rubber rod by vigorously rubbing the rod with the fur. By contrast, a glass rod loses electrons when it is rubbed by a silk cloth. What remains on the rod is a deficit of electrons (negative charge) and, therefore, a net positive charge.

If a rod with an excess of charge, either positive or negative, is put in contact with the metal of the electroscope, some of the excess charge flows on to the electroscope. If the electroscope is of the type pictured in the textbook, both leafs have the same charge and repel each other. The in-class version has a movable needle and a fixed metal plate, but the idea is the same. We see that the needle moves away from the plate because both have charge of the same sign and like charges repel.

If the rod is brought close to the rod, but doesn't touch, the electroscope leafs still separate. This is more subtle and more difficult to explain in words alone. See Figure 19.8a to see what happens. Here we see positive charge on the rod pulling negative charge to the nearby metal surface of the electroscope leaving positive charge on the two leafs. Note that the total charge on the electroscope is zero. What has happened is that the charge gets rearranged as a result of the rod being placed nearby. This suggests that the charge on the rod affects the nearby environment so that charge in the electroscope "feels" its presence. What happens is that an electric field is created by the charge on the rod. This electric field influences the distribution of charge on the electroscope.

We made sparks fly across a gap between two metal spheres. Electrons were transferred by a rotating belt on to one of the spheres. As described above, the charges create an electric field which spans the space between the two spheres. The electrons jump the gap and settle on the other sphere which is grounded. (Grounding has to do with establishing an electrical connection to the earth which has the effect of neutralizing the electrical charge on an object.) The flow of electrons between spheres results in the spark we see. But do we actually see the electrons? No, what we see results from the electrons striking atoms in the air between the spheres. The struck atoms become "excited" and when the atoms jump back to a deexcited state they emit light. That is what we see as the spark.

We are able to attract a metal can or even a large delicately balanced wood plank with charges on a rubber rod. We explain this by noting, as we explained the electroscope, that the presence of charge creates an electric field. The electric field influences the distribution of charge within the metal can, or even on the atoms in the wood. A negative charge has the effect of drawing positive charge closer to it, and a positive charge draws negative charge closer to it. The net effect is to create an attractive force.

Electric fields are illustrated in the animation we access here. We observe electrons in the environment of an electric field caused by two much larger charged objects, one positive and one negative. Note how a field is created by the charges. An electron "feels" the field and experiences a force whose magnitude depends on the strength of the field at the location of the electron. By convention, an electric field flows from positive charge to negative charge.

Another website, Charges and Fields, is similar to the previous one except that here you can experiment by creating more positive, negative and neutral objects with charge and noting how they effect electrons in their environment.

Now look at electrons in orbit around an atomic nucleus as depicted in the Web demo here.
This illustrates the similarity between the electric force and the gravitational force. The force between charges (Coulomb's Law) q1 and q2 separated by distance r is given by
Fcoul = kq1q2 / r2,
where k is a constant.
The gravitational force between masses m1 and m2 separated by distance r is given by
Fgrav = Gm1m2 / r2, where G is the gravitational constant.

Consider the analogy with gravitational potential energy. You know you can exert a force on an object and move it from one place to another, i.e., do work on it. If you raise an object in a gravitational field you increase its gravitational potential energy. The same concepts apply if you move a charge in an electric field by doing work on it. The work done in moving a charge from one place to another in an electric field, like moving a mass in a gravitational field, is equal to the change in the potential energy, electrical or gravitational, whichever applies. In many cases both apply.

It is commonly known, if not understood, that "Volts" have something to do with electricity. What has Volts is the electric potential? It is defined this way. If you have a object with charge Q and you move it from one place to another within an electric field by doing work on it so it gains an electric potential energy (U), its electric potential, measured in Volts (V), is given by V = U/Q. U is in Joules and Q is in Coulombs.

Do all atoms have electric charge?

Do all atoms have no charge?

Why do atoms have no electric?