Chemistry 9th Grade

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the mass number of an atom?

Back

The mass number is the total number of protons and neutrons in an atom's nucleus.

Front

How do you determine the number of neutrons in an atom?

Back

Subtract the atomic number from the mass number: Neutrons = Mass Number - Atomic Number.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.

Front

What is a chemical reaction?

Back

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.

Front

What is the law of conservation of mass?

Back

The law states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

What is an ion?

Back

An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Front

What is a covalent bond?

Back

A covalent bond is a type of chemical bond where two atoms share one or more pairs of electrons.

Front

What is an ionic bond?

Back

An ionic bond is a type of chemical bond formed through the electrostatic attraction between oppositely charged ions.