Chemistry First Semester Review

Front

What is a heterogeneous mixture?

Back

A mixture that does not have a uniform composition throughout, meaning the different components can be seen and separated easily.

Front

What is a covalent bond?

Back

A type of chemical bond where two atoms share one or more pairs of electrons.

Front

How many valence electrons does aluminum have?

Back

Aluminum has 3 valence electrons.

Front

How do you round 78.5 to one significant figure?

Back

78.5 rounded to one significant figure is 80.

Front

What happens when an atom loses a valence electron?

Back

It becomes a positive ion.

Front

What is a homogeneous mixture?

Back

A mixture that has a uniform composition throughout, where the different components are not distinguishable.

Front

Define an ion.

Back

An atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Front

What is the periodic table?

Back

A tabular arrangement of chemical elements, organized by their atomic number, electron configuration, and recurring chemical properties.

Front

What is the difference between ionic and covalent bonds?

Back

Ionic bonds involve the transfer of electrons from one atom to another, while covalent bonds involve the sharing of electrons.

Front

What is the significance of valence electrons?

Back

Valence electrons determine how an atom can bond with other atoms and are crucial in chemical reactions.