chemistry

chemistry

1. forming ions

   • ions are electrically charged particles formed when atoms lose or gain electrons.
   • this loss or gain leaves a full outer shell, so the electronic structure of an ion is the same as that of a noble gas

2. protons have a +1 charge

   • neutrons have a 0 charge
   • electrons have a -1 charge

3. element - where there is only one type of atom

4. compound - when there are two types of elements chemically joined together

5. mixture - any type of atom that isn't chemically joined together

6. the atomic number tells us how many protons there are in that element

   • the atomic number is always the smaller number

7. mass number tells us how many protons and neutrons there are

   • the mass number is always the bigger number

8. isotopes are atoms of the same element with the same number of protons and therefore electrons, but a different number of neutrons.

9. the relative atomic mass of an element is an average value that takes account of the abundance of the isotopes of the element

10. all atoms want to have a full outer shell so that they are stable and unreactive

11. an ion is when an atom gains or loses one or more electrons

12. the plum pudding model has a negative charge throughout the atom

    • the atom is solid

13. the nuclear model has electrons orbiting it

    • it has a positive charge focused in the nucleus
      • it is mostly empty space

14. alkali metals are soft enough to cut with a knife

    • have low melting and boiling points
      • have densities much lower than other metals