Fundamental chemistry

Question 1

Atom

Answer 1

Simplest particle that substances are made from – contain protons, neutrons and electrons.

Question 2

Element

Answer 2

A substance made of only one type of atom.

Question 3

Protons

Answer 3

+1 charged particle in the nucleus of an atom. It also has a relative mass of 1

Question 4

Neutron

Answer 4

Zero charged particle in the nucleus of an atom. It also has a relative mass of 1

Question 5

Electrons

Answer 5

-1 charges particles that orbit the nucleus in shells (energy levels). It also has a relative mass of 1/2000

Question 6

Atomic (proton) number

Answer 6

The number of protons an element has.

All atoms of the same element have the same number of protons. (Also the number of electrons for atoms)

Question 7

Mass number

Answer 7

The sum of the protons and neutrons in an atom.

Question 8

Isotope

Answer 8

Elements that have same number of protons but different number of neutrons.

Question 9

Relative Atomic Mass (Ar)

Answer 9

Compares the mass of atoms of the element with the 12C isotope.
It is an average value for the isotopes of the element.

Question 10

Relative Molecular Mass (Mr)

Answer 10

is the sum of the relative atomic masses (Big numbers on periodic table) of the atoms in the numbers of atoms shown in the formula.

Question 11

One Mole

Answer 11

Is the relative molecular mass of a substance, in grams.

Compared to 12g of Carbon-12

moles = mass (grams) ÷ RFM (Mr)