atoms and molecules

An atom is the smallest unit of matter that retains the properties of an element.

Molecules are groups of two or more atoms bonded together.

A neutron has no charge; it is neutral.

The three states of matter are solid, liquid, and gas.

There are 2 hydrogen atoms in a water molecule.

Yes, CO2 (carbon dioxide) is a molecule.

A chemical reaction is a process where substances (reactants) are transformed into different substances (products).

Electrons are negatively charged particles that orbit the nucleus of an atom and are involved in chemical bonding.

The periodic table is a chart that organizes all known elements based on their atomic number and properties.

An element is a pure substance that cannot be broken down into simpler substances by chemical means.