Science Substances Sem 2 Flashcards
Atoms
- Splitting Atoms creates nuclear power and atomic bombs.
- Smashing atoms together is where the sun gets energy from
- Made up of protons, neutrons and electrons
Protons and neutrons form the nucleus together
Metallic Metals
Elements that are metal. They have the following properties:
- Solids at room temperature (Except for
Hg)
- Can be made shiny or lustrous
- Conduct heat and electricity
- Can be beaten into shape or stretched into wire
Melts at very high temperatures (except for Hg)
Non metallic Elements
19 non-metals. These have the folliwing properties:
- Dull, not shiny
- Breaks or crumbles when bent
- Melts at low temperature
Do not conduct heat or electricity
Metalloids
A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals.
Alkali Metals
Group 1. Very reactive in water
Alkaline earth Metals
Group 2. Less reactive than alkali metals but still have all the metal properties
Transition Metals
In the block between group 2 and 13. They have metallic properties. Have many interesting properties and many form colorful compounds
Halogens
Group 17. They are very reactive. From left to right: Chlorine (gas), Bromine (liquid) and Lodine (solid)
Noble Gases
Group 18. All very unreactive but glow when exposed to electricity under special conditions
Monatomic Elements
An element that is made up of many individual atoms. Only 6 of these. Includes:
- Helium
- Neon
- Argon
- Krypton
- Xenon
- Radon
Molecular Elements
Most non-metallic elements are made up of molecules. Molecules are clusters of 2 or more atoms bonded together. In these elements, all molecules are identical.
Crystal Lattices
Are grid like structures
Molecular Formula
Molecular formulas are formulas for substances that are molecules. Other compounds that aren’t formulas for substances that are not molecules can also have formulas that represent the atoms in the compound
Mixtures
When two or more substances mix but do not form chemical bonds, it form a mixture. Air is a mixture of nitrogen, oxygen and carbon dioxide (a compound). Properties of a mixture is the same as the properties of its parts.
Separating compounds
Breaking chemical bonds. Energy needed: Electricity, extreme heat, other chemicals