ATI TEAS Guide To Science | The Atom Question Review

The atomic number reflects the number of protons in the atom. So, an atom with an atomic number of 6 would have 6 protons. The mass number reflects the number of protons and neutrons added together. So, an atom with 6 protons and a mass number of 14 would have 14 – 6, or 8, neutrons.

In the model of the atom, label A indicates an electron. Electrons orbit around the nucleus of the atom.

The approximate overall mass of an atom, in AMU, is equal to the number of protons plus the number of neutrons. The approximate overall mass of this atom is 19 + 23, or 42, AMU.

The overall charge is –1, and the mass number is 14. The charge is calculated by determining the difference between the number of protons and electrons. In this case, there are 7 electrons and 6 protons, which means that the atom has 1 more electron than the number of protons. The overall charge is therefore –1. The mass number is the number of protons plus the number of neutrons: in this case, 6 + 8 = 14.

Protons are positively charged atomic particles. In the model shown, label B indicates a proton.

Protons and neutrons have approximately the same mass, and neutrons have a neutral charge. Electrons are much smaller in mass than protons and neutrons.

In an atom, protons are positively charged, and electrons are negatively charged. When an atom has an equal number of protons and electrons, its overall charge will be neutral. When the atom has more electrons than protons, its overall charge will be negative. This atom has 11 electrons and 10 protons, so its overall charge is negative. The number of electrons exceeds the number of protons by 1, so the overall charge is –1.

The atomic number of an atom reflects the number of protons in the atom. This atom has an atomic number of 21, so it has 21 protons.