The nature of matter

Front

What is a chemical formula?

Back

A chemical formula is a way of expressing the composition of a substance using symbols for its constituent elements and numbers to indicate the ratio of atoms. For example, CH4 represents methane, which has one carbon atom and four hydrogen atoms.

Front

What are isotopes?

Back

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. This results in different atomic masses. For example, Carbon-12 and Carbon-14 are isotopes of carbon.

Front

What is an electron?

Back

An electron is a negatively charged subatomic particle found in all atoms. It orbits the nucleus and plays a key role in chemical bonding and electricity.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements chemically bond together. For example, NaCl (sodium chloride) is a compound made of sodium and chlorine.

Front

What is a chemical equation?

Back

A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products along with their quantities. For example, 2H2 + O2 → 2H2O.

Front

What is a molecule?

Back

A molecule is the smallest unit of a chemical compound that retains its chemical properties. It consists of two or more atoms bonded together, such as H2O (water).

Front

What is a proton?

Back

A proton is a positively charged subatomic particle found in the nucleus of an atom. The number of protons determines the element's identity.

Front

What is a neutron?

Back

A neutron is a neutral subatomic particle found in the nucleus of an atom. Neutrons contribute to the atomic mass but do not affect the charge of the atom.

Front

What is the atomic number?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity and its position on the periodic table.

Front

What is a chemical reaction?

Back

A chemical reaction is a process in which substances (reactants) are transformed into different substances (products) through the breaking and forming of chemical bonds.