An atom is the smallest unit of an element that retains all the properties of that element.
Name the three subatomic particles in an atom.
Protons, neutrons, and electrons.
What is the charge of an electron?
Negative.
Where are protons and neutrons located in an atom?
In the nucleus.
What does the atomic number represent?
The number of protons in an atom.
What is a molecule?
A molecule is a group of two or more atoms bonded together.
What is the difference between an element and a compound?
An element is a pure substance made of only one kind of atom, while a compound consists of two or more elements chemically combined.
What is the periodic table?
A chart of the elements arranged according to their atomic number, usually in rows, so that elements with similar atomic structure appear in vertical columns.
Who is credited with creating the first periodic table?
Dmitri Mendeleev.
What is an ion?
An atom or group of atoms that has a positive or negative charge due to the loss or gain of one or more electrons.
What are isotopes?
Atoms of the same element with different numbers of neutrons and therefore different atomic masses.
Define the term 'relative atomic mass'.
It is the weighted average mass of an atom of an element compared to one twelfth of the mass of a carbon-12 atom.
What is a covalent bond?
A chemical bond that involves the sharing of electron pairs between atoms.
What is a chemical reaction?
A process that leads to the transformation of one set of chemical substances to another.
What do we call substances that speed up chemical reactions without being consumed?