science revision

what is an Element?

A ‘pure’ substance, is comprised of 1 type of atom.

What is a molecule?

2 or more type of atoms that are bonded together

What is a compound?

2 or more different types atoms that are combined by chemical bonds

what type of charge does a proton have?

positive

What type of charge does a neutron have?

No charge, neutral

What type of charge does an Electron have?

Negative

How to calculate amount of neutrons using the atomic chart

mass number - atomic number = neutrons

How to calculate amount of protons / electrons using the atomic chart

atomic number = protons / electrons

Where are electrons held in Bhor’s model?

In the electronic shells around the nucleus

How many electrons can be held in each shell?

2, 8, 8, 18

where are the neutrons and protons in Bohr’s model?

In the nucleus

What is an Ion?

An ion is when the number of electrons in an elements are changed, changing the number of electrons won’t change the element but will change it’s chemical properties

Why do Ions occur?

Atoms always want to have full electron shells, an atom can gain or loose an electron to make a full outer shell

What is a positively charged ion called?

A Cation

What is a negatively charged ion called?

An Anion

How to write the symbol when an element gains an electron.

X 1-

X stands for the element symbol, the number 1 is changed for however many electrons are gained

How to write a symbol for when an atom looses an electron

X 1+

X stands for the element symbol, the number 1 is changed for however many electrons are lost

Nuclide symbol formation

Refer to image attached

name the weight for protons, neutrons, and electrons

protons = 1 amu

neutrons = 1 amu

electrons = 0 amu

What is an isotope?

When an element protons stay the same but it’s atomic mass and neutrons differ