- Involved in studying, varifying information (eg the periodic table -> Describes the elements -> pure susbtances made of only one kind of atom),and publishing.
- An ionic bond is a bond between a negative ion and a positive ion (so a anion and a cation)
- An convalent bond is a bond between 2 non-metals
- An ion is a charged particle
- An anion is formed when an particle gains electrons
- An cation is formed when an particle loses electrons
- We can use modesl(e.g Lewis dot diagrams) to show bonding
- Atoms will lose or gain electrons to achieve noble gas $`e^-`$ configuration $`\rightarrow`$ The most common stable ion. (eg, if $`Na`$ loses electrons, it becomes like $`Ne`$, if $`Cl`$ gains an electron, it becomes like $`Ar`$)
- To show that atoms are different than ions, we put square brackets around it $`[Na]`$, then we put superscript on the top right to show its charge, $`[Na]^+`$ (if the charge is only a $`\pm 1`$, we just put a $`+`$ instead of $`+1`$)
- $`Ca \rightarrow`$ Calcium ion $`Ca^{2+}`$ `(Cation)`
- $`CO_3 \rightarrow`$ Carbonate ion $`CO_3^{2-}`$ `(Anion)`
- Calcium carbonate
- The ones that are not multi-valent are:
- The first 20 elements
- alkali metals
- alkaline earth metals
- non-metals (the ones hugging the staircase are also non-metals (some of the metalloids))
- halogens
- noble gases
- Going down diagonally from aluminium, we get a pattern of 3+, 2+, 1+ of charge. Aluminium has a charge of 3+, Zinc has a charge of 2+, and silver has a charge of 1+, and they
are all mono-valent. (not multi-valent)
- If there is more than one polyatomic ion in a formula unit, then surround the ion with brackets