Chemistry Review Quiz

A certain atom of oxygen contains 8 protons, 8 neutrons, & 8 electrons. Another atom of unknown identity contains 9 protons. Which of the following MUST be true about this unidentified atom?

• It has 9 neutrons in its nucleus.

• It is an isotope of oxygen.

• Its atomic mass is a decimal number.

• It cannot be an atom of oxygen.

An atom of neon has 8 valence electrons. What will an atom of neon MOST likely do to be stable?

• Gain 1 electron

• Lose 2 electrons

• Lose 8 electrons

• Neither gain nor lose any valence electrons

When a chemical reaction happens

• bonds must be broken and reformed
• chemicals don't collide
• atoms keep their arrangements
• chemicals keep their same properties

The higher the ionization energy...

• the more attracted the valence electron is to the nucleus so it is harder to remove

• the less attracted the valence electron is to the nucleus so it is easier to remove

• the more attracted the valence electron is to another electron, so it is harder to remove

• the more repelled a valence electron is to another electron, so it is easier to remove

Why does ionization energy decrease going down a group?

• Adding more energy levels makes the ve- further from the nucleus so it is easier to remove

• There are more valence electrons in the outer shell so the ve- is easier to remove

• There are more protons in the nucleus so the ve- is easier to remove

• There are less protons in the nucleus so the ve- is easier to remove

Why does electronegativity increase across a period?

• Adding more energy levels makes the ve- further from the nucleus
• There are more valence electrons in the outer shell
• There are more protons  in the nucleus
• There are less protons in the nucleus

Which is smaller... Mg or Mg²⁺ ?

• Mg because it gains an energy level
• Mg due to extra electron repulsion
• Mg²⁺ because of extra electron repulsion
• Mg²⁺ because it loses an energy level

List the following from largest to smallest atomic radius.
P, Cs, Co, Sr

• P, Co, Sr, Cs
• P, Cs, Co, Sr
• Cs, Sr, Co, P
• Sr, Cs, Co, P

What happens to atomic radius across a period?

• the atoms get bigger because the nucleus is bigger as more protons are added

• the atoms get bigger because there are more ve-

• the atoms get smaller because with more attraction to the extra protons, the e- cloud moves closer to the nucleus

• the atoms get bigger because there are more energy levels

What are the positively charged particles in an atom?

• Protons
• Neutrons
• Electrons