Core charge _____? (Select all correct answers)

• Is the number of protons - the number of inner shell electrons.

• Increases going right on a period.

• Decreases going right on a period.

• Is the number of protons - the number of valence shell electrons.

Answer explanation

Core charge is the effective nuclear charge experienced by a valence electron.

It is always positive.

It decreases going down a group and increases across a period.

Which of these groups are considered 'main-group elements'?

• Groups 1,2

• Groups 3-13

• Groups 1,2, 13-18

• Groups 4-8, 13-18

Why are they referred to as 'main-group elements'?

• They are abundant in the universe.

• They are scarce in the universe.

• They are more important than other elements.

• They all have similar energy levels.

What does the period number tell you?

• The number of valence electrons.

• The number of protons and electrons.

• The number of electron shells occupied.

• The amount of energy of the elements in the period.

What does the group number tell you?

• The block that the elements are in. (s, p, d, f blocks)

• The number of electron shells occupied.

• The number of inner shell electrons.

• The number of valence shell electrons.

Elements can be classified as either _____ or _____?

• Protons or electrons.

• Cations or anions.

• Metals or non-metals.

• Positively or negatively charged.

True or false: Non-metals are found to the left of the staircase. (As shown in the image)

• True

• False

Answer explanation

Metals are found to the left of the staircase.

What are elements found in group 3-12 referred to as?

• Noble gases

• Transition metals

• Alkaline earth metals

• Metalloids

Answer explanation

Group 1 is Alkali metals, Group 2 is Alkaline Earth metals,

Metalloids are found at the staircase and comprise of Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium and Astatine.

Low melting point, weak, not malleable, gas at room temperature, forms an anion. These are characteristics of _____?

• Metals

• Non-metals

What are metalloids?

Answer explanation

Metalloids share characteristics of both metals and non-metals.