Unit Test Review (Science)

Each columon in the periodic table is called a ________________ of elements.

Each row across the periodic table is called a ______.

In ____, Dimitri Mendeleev made a chart of the known elements.

An atom is the smallest particle of matter in the universe.

_______ have a +(postive) charge.

The L shell holds _ electron(s).

The nucleus is made up of protons and electrons packed tightly together.

Every atom in the world is exactly alike.

The symbols for the elements are different all over the world.

There are more than ___ different elements identified at the present time.

The first shell is the _ shell. (Hint: It is the closet to the nucleus and has the least amount of energy.)

________ have a -(negative) charge.

An atom is made up of what part(s).

The k shell holds _ electron(s).

Atomis mass of an atom is the total number of protons and neutrons in the nucleus of the atom.

The atomic number of an atom is the number of _______ in an atom.

If a shell is a valence shell, it can hold only 18 electrons, even if it is the M shell.

An electron is the smallest part of the atom.

In modern atomic theory, electrons are arranged into energy levels or shells.

________ have no charge.