ELEMENTS Flashcards
How many elements are there?
92
Can elements be split up into other substances? - 2
- No - they are made of just one type of particle called an ATOM.
- The atoms of each element are different.
Who came up with the theory that all matter was made up of very small building blocks he called ATOMOS?
DEMOCRITUS - he wasn’t a scientist so no one paid any attention to him until the 1800s
What does ATOMOS mean?
It is the Greek word for ‘cannot be split up’
What was John Dalton’s Atomic Theory - 5 points
- Elements made of tiny particles called Atoms
- All atoms of a given element are identical
- Atoms of a given element are different to those of other elements and can be distinguished by their weight
- Atoms of one element can be combined with other to form chemical compounds
- Atoms cannot be created, divided into smaller particles or destroyed
Name 6 physical properties of metals
- Shiny
- Good conductors of heat
- Good conductors of electricity
- High melting point
- Ductile (most metals can be drawn out into thin wires)
- Malleable (most metals can be hammered into thin sheets)
Name 7 physical properties of non-metals
- Not shiny
- Poor conductors of heat
- Poor conductors of electricity
- Low melting point
- Brittle (breaks easily)
- Not ductile
- Not malleable
What is a chemical reaction?
A change in the way the atoms are grouped together
Elements are divided into 2 groups, what are these?
Metals and non-metals
What does the term ‘carat’ mean for gold? - 2
- The purity.
2. The higher the carat the purer it is
What colour is chlorine gas?
Yellowish-green
What % of the Earth’s atmosphere is Nitrogen?
78%
Is mercury a solid, liquid or gas at room temperature?
Liquid
Give 2 parts of the human body that contain a lot of calcium
- Bones
2. Teeth
