Atoms

Atoms :

1. Atoms are the smallest particle of a chemical element that can exist alone.

Atoms are made up of protons, neutrons and tiny electrons.

Protons are positively charged, neutrons are neutral.

Both protons and neutrons are found in the nucleus, giving mass to the atom.

Electrons are negatively charged and float in shells around the nucleus.

Electrons are so tiny that they don't add mass to the atom.

Activities on Atom

2. Atoms always have equal numbers of protons and electrons.

Their positive and negative charges cancel each other out, to make atoms neutral overall.

Protons are found in the nucleus and electrons are found in shells or energy levels around the outside.

3. Electrons in atoms are found in shells, and atoms can lose or gain electrons to become stable.

Atoms are stable when their outermost shell is full of electrons.

Gaining electrons means atoms become more negative than positive, so become negative ions.

Losing electrons to have a full shell means the atom will have more positive protons, so becomes a positive ion