Science Study

What is the Octet Rule?

Atoms are stable with 8 valence electrons in their outer shell.

What are the exceptions to the Octet Rule?

Hydrogen and helium, which only need 2 electrons to be stable.

What do Lewis dot diagrams illustrate?

The valence electrons of an atom.

How do covalent bonds form?

Electrons are shared between atoms to achieve full valence shells.

What is a nonpolar covalent bond?

Electrons are shared equally between atoms with similar strength.

What is a polar covalent bond?

Unequal sharing of electrons, leading to a partial charge in the molecule.

Give an example of a polar covalent bond.

Water (H2O).

What is an ionic bond?

A bond formed by the attraction between oppositely charged ions.

How do ionic bonds form?

One atom gives up electrons while another atom accepts them.

What types of elements typically form ionic bonds?

Usually between metals and nonmetals.

Provide an example of an ionic compound.

Sodium chloride (NaCl).

What is the charge balance in ionic compounds?

Ionic compounds are neutral; total positive charge equals total negative charge.

What do chemical formulas indicate?

The elements in a molecule and the quantity of each present.

What does the coefficient in a chemical formula represent?

The number of whole distinct molecules of that substance.

What does a subscript in a chemical formula indicate?

The number of atoms of an element in a molecule.

What happens if no number is written in a chemical formula?

It is assumed to be 1.