Atomic Structure

A neutral element on the periodic table has an atomic number of 13 and a mass number of 27.0. The number of protons, neutrons and electrons it has is:

• 13 protons, 13 neutrons, 14 electrons

• 14 protons, 14 neutrons, 13 electrons

• 13 protons, 14 neutrons, 15 electrons

• 13 protons, 14 neutrons, 13 electrons

The current accepted model of the atom has the sub-atomic particles arranged as:

• Protons, neutrons and electrons randomly scattered.

• Protons and neutrons in the nucleus with electrons forming a charge cloud around the nucleus.

• Neutrons and electrons in the nucleus with protons orbiting the nucleus in shells.

• Protons and electrons in the nucleus with neutrons orbiting the nucleus in shells.

The mass number of an element is derived from:

• The number of electrons and protons.

• The number of electrons.

• The number of protons and neutrons.

• The number of protons.

An ion is an element that has:

• Lost or gained protons

• Lost electrons only

• Lost or gained electrons

• Lost neutrons

An isotope is a different form of the same element in which the number of:

• Electrons varies

• Neutrons varies

• Protons varies

• Electrons and protons varies

State the maximum number of electrons in the first three shells of an atom

• 8,8,18

• 2,8,12

• 2,8,8

• 2,8,18

In the ground state, the electrons of phosphorus occupy

• 1 shell

• 2 shells

• 3 shells

• 4 shells

When a fluoride ion forms a fluorine atom, which one of the following does not change?

• The charge on the particle

• The number of inner shell electrons

• The number of electrons in the valence shell

• The diameter of the particle

The element carbon has three naturally occurring isotopes. Which one of the following statements regarding isotopes is correct?

• All isotopes have the same atomic number

• All isotopes have the same mass number

• The chemical reactions of the different isotopes are not the same

• The heaviest isotope has the most electrons

What is the maximum number of electrons that can occupy the sixth electron shell?

• 8

• 18

• 50

• 72