Front

If sodium loses an electron, it becomes

Back

positively charged

Front

Iron gains three electrons and has a 3- charge.

Back

Iron ion has a negative charge.

Front

An atom that gains or loses an electron is called an ion.

Back

Ions can be positively or negatively charged.

Front

An atom with different numbers of neutrons is called an isotope.

Back

Isotopes have the same number of protons.

Front

Aluminum has 13 protons.

Back

Aluminum is element number 13.

Front

Iodine has 74 neutrons (based on iodine-127).

Back

Iodine-127 is a stable isotope.

Front

Neon has 10 electrons.

Back

Neon is a noble gas.

Front

Chlorine has 18 neutrons (based on chlorine-35).

Back

Chlorine-35 is a stable isotope.

Front

Elements are distinguished by the number of protons in their nuclei.

Back

The atomic number defines the element.

Front

The first energy level can hold 2 electrons.

Back

This is the maximum capacity of the first shell.