Review of Periodic Table 2022

Which of the following elements have similar chemical and physical properties?

• lithium & beryllium

• calcium & barium

• aluminum & sulfur

• zirconium & tungsten

Answer explanation

Elements in the same group have similar chemical properties because they have the same number of valence electrons (and do the same thing to obey the octet rule).

Which family is the most reactive nonmetal family?

• alkali metals

• alkaline earth metals

• halogens

• noble gases

• oxygen family

Answer explanation

Nonmetals are on the right side of the metalloids. Halogens are the most reactive because they only have to gain one electron in order to obey the octet rule.

Which family is the most reactive metal family?

• alkali metals

• alkaline earth metals

• halogens

• noble gases

• oxygen family

Answer explanation

Metals are on the left side of the metalloids. Halogens are the most reactive because they only have to lose one electron in order to obey the octet rule.

Which family is known as inert?

• alkali metals

• alkaline earth metals

• halogens

• noble gases

• oxygen family

Answer explanation

Since they already have a full octet of valence electrons they have no reason to react

What is the oxidation number of elements in the nitrogen family?

• +5 because 5 electrons are gained

• -5 because 5 electrons are gained

• +3 because 3 electrons are gained

• -3 because 3 electrons are gained

Answer explanation

Since these elements have 5 valence electrons, they have to gain 3 more in order to have a full octet. Since they have more electrons than protons, they form anions with a negative charge.

Which of the following is a chemical property of a metal?

• brittle

• reacts with acid

• lustrous

• does not react with CuCl₂

Which of the following is a reason that the nuclear pull gets stronger from left to right across a period?

• There are more protons in the nucleus pulling on valence electrons that are in the same energy level.

• There are more energy levels in the atom.

• There are more inner electrons in the atom.

• There is decreased nuclear shielding.

Answer explanation

Elements in the same period have the same number of energy levels, inner electrons, and amount of shielding since their valence electrons are in the same principal energy level.

Put the following elements in order from the most reactive to the least reactive.

• Be, Mg, Ca, Ba

• Ba, Ca, Mg, Be

• Mg, Ca, Be, Ba

• Ca, Be, Mg, Ba

Answer explanation

The metal with the weakest nuclear pull will be the most reactive since it will be easier to remove its valence electrons.

Put the following elements in order from the most reactive to the least reactive.

• Ar, Cl, S, P

• Cl, S, P, Ar

• P, S, Cl, Ar

• Ar, P, S, Cl

Answer explanation

Nonmetals with a stronger nuclear pull will be more reactive because it is easier for them to gain electrons (more electronegative). But remember that noble gases are inert since they already have 8 valence electrons.

Put the following in order of decreasing atomic radius.

• Ge, Hg, In, P

• P, In, Hg, Ge

• P, Ge, In, Hg

• Hg, In, Ge, P