Module 1.3 Flashcards
Elements, componds and mixture. Differrnces b/w mixture and compound.
1
Q
What are atoms?
A
Atoms are the smallest particles of matter, thaat we cannot break down further by chemical means.
2
Q
What are elements?
A
An element contains only onee kind of atom.
3
Q
How many elements have been found and made?
A
90 elements natural. 30 made in a lab.
4
Q
What iss the periodic table?
A
- Gives names and symbols for elements.
- The column and row have common characteristic.
- The rows are called periods
- Zig zag line separate metals from non metals (non-metals to the right)
5
Q
Properties of metals
A
- Good conductors of heat and electricity
- High melting and boiling points.
- Malleable (hammered) and Ductile (drawn into wires.
- Look shiny when polished.
- Sonorous
- High density (heavy)
- Form positive ions in reaction
- React with oxygen to form oxides that are bases.
6
Q
Properties of non metals
A
- Do not conduct electricity or heat.
- Low melting boiling points (many r gases)
- Solids are BRITTLE
- Solids are non malleable and non ductile
- Solids look dull
- Solids have low density
- Solids break up when struck (non sonorous)
- Often form negative ions in reactions
- React with oxygen to form ACIDIC oxides.
6
Q
Properties of non metals
A
- Do not conduct electricity or heat.
- Low melting boiling points (many r gases)
- Solids are BRITTLE
- Solids are non malleable and non ductile
- Solids look dull
- Solids have low density
- Solids break up when struck (non sonorous)
- Often form negative ions in reactions
- React with oxygen to form ACIDIC oxides.
7
Q
What are compunds
A
A compound is made of atoms of different elementd bounded together. It is described by a formula.
8
Q
What is a mixture
A
A mixture contains different substances that are NOT BONDED together.
9
Q
List the signs of a chemical change.
A
- One or more new chemical substances are formed.
- Energy is taken in or given out, during a reaction.
- The change is usually difficult to reverse.
10
Q
When is a change a physical change
A
When no new substances are formed
