LEC 3

Question 1

What are chemical bonds?

Answer 1

Formed when 2 elements combine and are chemically altered.

Question 2

What are molecules?

Answer 2

2 or more atoms chemically bonded

Question 3

What is a compound?

Answer 3

Two or more DIFFERENT elements chemically bonded

Eg: (sodium(Na)+ chloride(Cl) <> NaCl_Salt)

Question 4

What are Macromolecules?

Answer 4

Very large molecules that contains many atoms

Question 5

What is a molecular formula?

Answer 5

How molecules are represented- using symbols and numbers

Describes: The types and amount of atoms in a molecule

Question 6

What are chemical bonds?

Answer 6

The interactions of electrons in the outermost shell of the atom

Question 7

What is the outer most shell of the atom called?

Answer 7

Valence shell

(It’s electrons are called “valence electrons”)

Question 8

What is the function of the valence electrons? (Outermost electrons)

Answer 8

Allow atoms to Interact with other atoms

Question 9

What is an ionic bond?

Answer 9

Transfer of metal electrons between atoms

-(One Atom “donates” and another “accepts” electrons)
-Fully transfer electrons

Question 10

True or false

All the particles (P,N,E) are Ions?

Answer 10

TRUE

Question 11

What makes a atom reactive?

Answer 11

The last election shell not having 8 electrons

Reactive - unstable- moves

Question 12

What makes an atom inert?

Answer 12

Having 8 electrons on the last shell

(Non- reactive- inert- stable- don’t move)

Question 13

True or false
NaCl is and example of ionic bond?

Why?

Answer 13

TRUE

Two different atoms transfer electrons to make a new chemical element.

Sodium (Na) and chlorine (Cl) makes&raquo_space; NaCl-sodium chloride - salt

Question 14

What are covalent bonds?

Answer 14

2 or more non-metals share electrons

• partially sharing
  -strongest type of chemical bond
  -Eg: hydrogen bond (H2)
  OR (H2O) hydrogen and oxygen- water

Question 15

Extra notes
Electrons sharing - covalent bonds

Answer 15

1.Single covalent bond
- shares only ONE pair of electrons (CH4, methane)

2. Double covalent bond
   -share TWO pairs of electrons (O2, oxygen)
3. Triple covalent bond
   -shares THREE pairs of electrons (N2, nitrogen gas)

Question 16

List the types of covalent bond?

Answer 16

1. Non- polar Covalent Bonds
2. Polar Covalent Bonds

Question 17

What is a non-polar covalent bond?

Answer 17

Equal sharing of electrons
- 2 or more non-metals atoms

Eg: -carbon and hydrogen
- CH4, methane

Note- atoms sharing electrons of the same elements such as:
-Hydrogen (H2)
-Oxygen (O2)
-Nitrogen (N2)
All non-polar bonds

Question 18

What are Polar Covalent Bonds?

Answer 18

Unequal sharing of electrons
-sharing between 2 or more non-metals atoms

Question 19

TRUE OR FALSE

To form a water droplet (any droplet) the atom have to be partial positive and partial negative?

(Partial hydrophobic and partial hydrophilic)

Answer 19

TRUE

Question 20

1. What is hydrophobic?

Answer 20

1. Fears water/Water hating