Define atom.
The smallest unit of an element, consisting of protons, neutrons, and electrons.
What is the atomic number?
The number of protons in the nucleus of an atom, defining the element.
True or false: Isotopes have the same number of protons but different neutrons.
TRUE
Fill in the blank: Molecules are formed when _______ bond together.
atoms
What is a compound?
A substance formed when two or more different elements chemically bond.
Define ionic bond.
A chemical bond formed through the transfer of electrons from one atom to another.
What is a covalent bond?
A bond formed when two atoms share one or more pairs of electrons.
Fill in the blank: Acids release _______ ions in solution.
hydrogen
Define pH scale.
A scale used to measure the acidity or alkalinity of a solution, ranging from 0 to 14.
What is stoichiometry?
The calculation of reactants and products in chemical reactions based on balanced equations.
What is activation energy?
The minimum energy required for a chemical reaction to occur.
Define catalyst.
A substance that increases the rate of a chemical reaction without being consumed.
What is the law of conservation of mass?
Matter cannot be created or destroyed in a chemical reaction.
True or false: Chemical equations must be balanced to obey the law of conservation of mass.
TRUE
What is a solution?
A homogeneous mixture of two or more substances, typically a solute dissolved in a solvent.
Define solubility.
The ability of a substance to dissolve in a solvent at a given temperature and pressure.
What is an element?
A pure substance made of only one type of atom.
Signs of chemical change?
Gas formation, precipitate, colour change and heat/light released.
The number of protons = the number of electrons = ?
Atomic number
Number of protons + number of neutrons = ?
Mass number
Mass number - atomic number = ?
Number of neutrons
