Elements Atoms Mendeleers Tables

Question 1

Who came up with the model of the atom

Answer 1

John Dolton

Question 2

4 parts of an atom:

Answer 2

Electron
Protron
Neutron
Nucleus

Question 3

The first alkali metal

Answer 3

Lithium

Question 4

Group 7 elements are called…

Answer 4

Halogens

Question 5

These elements are very unreactive

Answer 5

Noble gases

Question 6

A green gas that is a halogen

Answer 6

Chlorine

Question 7

What is relative atomic mass?

Answer 7

John Dalton theory
All atoms of a certain element have the same mass BUT that atoms of different elements have different masses.
Hydrogen was given mass of 1 - other elements are compared to this so we say the masses of the atoms are RELATIVE to hydrogen.

Question 8

When magnesium reacts with oxygen it burns to form magnesium oxide. The mass is the same before and after. Why?

Answer 8

The atoms of the reactants are just REARRANGED. NO atoms are LOST or GAINED. The mass of the product made is therefore the same as the reactants.