Atoms, PT, conservation of matter

Group which contains 1 valence electron and includes the most reactive metals?

• Family 1, alkali metals

• Family 2, alkaline earth metals

• Family 18, noble gases

• Family 17, halogens

Elements in the same vertical column (up and down) of the periodic table:

• period

• group/family

• valence electrons

• energy levels

Elements in the same horizontal row (across) of the periodic table:

• period

• group/family

• valence electrons

• energy levels

Elements in the same period have:

• the same atomic mass

• the same physical properties

• the same number valence electrons

• the same number of energy levels

Elements in the same group/family have:

• the same atomic mass

• the same physical properties

• the same number valence electrons

• the same number of energy levels

An atom or group of atoms that has an electric charge (unbalanced number of protons and electrons) is called:

• an isotope

• a metalloid

• an ion

• a metal

Atoms with the usual number of protons for an element, but a different number of neutrons are called:

• isotopes

• metalloids

• ions

• metals

This identifies an element and tells the number of protons in the nucleus of an atom of that element:

• atomic mass number

• mass number

• chemical symbol

• atomic number

A neutral atom has the same number of:

• neutrons and protons

• neutrons and electrons

• protons and neutrons

• protons and electrons

Tags

NGSS.MS-PS1-1

A one or two letter representation of an element:

• atomic mass number

• chemical formula

• chemical symbol

• atomic number