Covalent Molecules

Question 1

What are covalent bonds?

Answer 1

formed when non-metal atoms share electrons in order to obtain a full valence electron

Question 2

How does the covalent bond work?

Answer 2

electromagnetic attraction due to the positive nuclei of each atom and the negative electrons btw

Question 3

What are the covalent bond types?

Answer 3

single bond

double bond

triple bond

Question 4

How does the single bond work?

Answer 4

each atom gives 1 electron to share

therefore share 2 electrons

Question 5

How does a double bond work?

Answer 5

each atom gives 2 electrons

therefore, they share 4 electrons

Question 6

How does a triple bond work?

Answer 6

each atom gives 3 electrons

therefore, 6 electrons are shared

Question 7

What are differences btw ionic and covalent bonds?

Answer 7

ionic
btw metal & non-metal
electrons transferred
attraction btw positive & negative ions
exist as lattices
therefore, formula unit same but size differs

covalent
btw > (or equal to) 2 atoms
electrons shared
attraction btw nuclei & electrons
exist as molecules
therefore, same number & atom type

Question 8

What do I use to draw covalent bonds

Answer 8

Lewis structures

Question 9

What are unpaired electrons?

Answer 9

electrons that are able to form bonds

Question 10

What are paired electrons?

Answer 10

lone pairs

not able to form covalent bond

Question 11

How do I draw a Lewis structure?

Answer 11

1. identify bonding electrons (last group # = # of valence electrons)
2. find options - ALL BONDING ELECTRONS MUST BE USED
3. draw Lewis structure for each atom involved
4. atom that forms the most bonds goes in middle
   any atom that only form 1 bond go on outside
5. check each atom has full valence shells

Question 12

What are common covalent compounds?

Answer 12

H20 = water = dihydrogen monoxide

NH3 = ammonia = nitrogen trihydroxide

CH4 = methane = carbon tetrahydroxide

Question 13

What are diatomic elements and which ones are they?

Answer 13

covalent elements that exist as molecule wt 2 atoms

H2, N2, O2, F2, Cl2, Br2, I2
H, N, O + halogens

Question 14

How are covalent compounds named?

Answer 14

1. follow element order as in formula
2. where there is >1 atom ( for 1st element) & for 2nd element ALWAYS use prefixes:

1- mono
2 - di
3 - tri
4 - tetra
5 - penta
6 - hexa
7 - heat
8 - octa
9 - nona
10 - deca

3. add -ide to 2nd element

Question 15

How do you write equations from scratch?

Answer 15

1. reaction into word equation
2. identify bonding in reactants & products (ionic / covalent / metallic)
3. look out for DIATOMIC ELEMENTS / ACIDS!!!
4. skeleton equation into chemical formula
5. balance
6. add state symbols