diff --git a/Grade 10/Science/SNC2DZ/Unit 1: Chemistry.md b/Grade 10/Science/SNC2DZ/Unit 1: Chemistry.md
index 76846b1..6186137 100644
--- a/Grade 10/Science/SNC2DZ/Unit 1: Chemistry.md	
+++ b/Grade 10/Science/SNC2DZ/Unit 1: Chemistry.md	
@@ -6,10 +6,17 @@
 ## Atoms
 - Atoms are the smallest unit of an element that still retains its properties
 - Atoms are made of subatomic particles
+- Relative Charge: compared to something. 
+- AMU = atomic mass units
+- models allow people to make accurate preictions about the behaviour of matter
+- atmoic notation $`_{19}K`$
+- an isotope is an atom (or atoms) of an element with a unique # of neutrons
 
-|Name|Symbol|Relative mass|Location|Relative Change|
-|:---|:-----|:------------|:-------|:--------------|
-|
+|Name     |Symbol|Relative mass (amu)|Location|Relative Charge|
+|:--------|:-----|:------------------|:-------|:--------------|
+|Protons  |$`p^+`$|       1          |nucleus | $`+1`$        |
+|Neutrons |$`n^0`$|     1            |nucleus | $`0`$         |
+|Electrons|$`e^-`$|$`~\frac{1}{2000}`$|in orbit around nucleus (shell, energy level)|$`-1`$|
 
 ## IUPAC
 |Letter|Definition|