05 Atomic Structure Flashcards
Define “element”.
Pure substances of only 1 atom type.
Describe the difference between a molecule and a compound.
A molecule is two atoms of the same element chemically bonded together, however a compound is two or more different types of atoms chemically bonded together.
What are the 3 main sub-atomic particles?
Protons (+)
Neutrons (0)
Electrons (-)
Define “nucleus”.
Centre of the atom -> contains protons and neutrons.
Define “electron shells”. Also describe how many electrons can fit into the first 3 shells.
This is where the electrons are found. The first shell can hold up to 2 electrons, the second up to 8 electrons, and the third also up to 8 electrons.
What are atoms measured in?
Atomic mass.
Name the first 10 elements.
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Name elements 11-20.
Sodium Magnesium Aluminium Silicon Phosphorous Sulfur Chlorine Argon Calcium Potassium
Name 5 general properties of metals.
- Usually solids at room temperature
- Shiny
- High melting point
- Conduct electricity and heat
- Malleable/Ductile
Name 4 general properties of non-metals.
- Can be solids, liquids or gases at room temperature
- Dull
- Poor conductors of heat and electricity
- Brittle
Define “mass number/nucleon number”
Sum of the no. of protons and neutrons in the nucleus. Basically its entire mass. Usually the bigger number.
Define “atomic number”
No. of protons in the nucleus. Usually the smaller number.
Define “isotope”.
Isotopes are atoms of the same element, but with different amounts of neutrons.
Define “ions”. (NOT the atom)
When an atom gains an electron, it becomes negatively charged. When it looses an electron, it becomes positively charged.
