Group 7 and Period 3 Trends

Flashcards covering key vocabulary and concepts related to Group 7 elements and Period 3 trends in chemistry.

Halogens

The elements of Group 7 in the periodic table that accept one electron to form anions.

Halides

Anions formed from halogens when they gain electrons.

Diatomic molecules

Molecules made up of two atoms, such as Cl2 for chlorine.

Van der Waals forces

Weak attractive forces among molecules that increase with molecular size.

Oxidizing agent

A substance that causes another to lose electrons during a chemical reaction.

Oxidation

The process where a substance loses electrons.

Group 7 Trends

Trends observed in Group 7 elements such as changes in molecular size, physical state, density, and oxidizing power as you descend the group.

Density

The mass per unit volume of a substance, which increases in Group 7 as the group is descended.

Physical state of halogens

Varies by element: fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid at room temperature.

Properties of Metals

Characteristics including high melting and boiling points, high density, and good conductivity.

Properties of Non-Metals

Characteristics including low melting and boiling points, low density, and poor conductivity.

Cations

Positively charged ions formed by metals.

Anions

Negatively charged ions formed by non-metals.

Insulators

Materials that poorly conduct heat and electricity, typically non-metals.