Lecture 1: Foundation of Chemistry Review

Question 1

What are the three major components of an atom?

Answer 1

Proton, Neutron, Eletron

Question 2

What is the positively charged component of an atom?

Answer 2

proton

Question 3

What is the negatively charged component of an atom?

Answer 3

electron

Question 4

What is the neutral charged component of an atom?

Answer 4

neutron

Question 5

What defines a specific atom?

Answer 5

the number of protons in each specific atom (if the number of protons change, the atom changes).

Question 6

Which two components make up the nucleus and overall mass of an atom?

Answer 6

Protons and Neutrons

Question 7

How do electrons affect the mass of an atom?

Answer 7

They don’t affect the mass of an atom because they are so small, their mass is negligible.

Question 8

What is the difference between an ion and isotope?

Answer 8

Ions are versions of an atom that differ in number of electrons and Isotopes are versions of an atom that differ in number of neutrons.

Question 9

Other than number of neutrons, how do isotopes differ?

Answer 9

They differ in mass.

Question 10

Other than number electrons, how do ions differ?

Answer 10

Charge of atom

Question 11

What is a cation?

Answer 11

Positively charged ion that has more protons than electrons.

Question 12

What is an anion?

Answer 12

Negatively charged ion that has more electrons and protons.

Question 13

When are atoms most stable?

Answer 13

When their “electron shells” are full. (and when something is more stable it is less likely to change or break apart easily).

Question 14

What are covalent bonds?

Answer 14

When atoms are bonded together by sharing electrons

Question 15

What are ionic bonds?

Answer 15

Attraction of positive and negative charges. These bonds are broken more easily than covalent bonds. (i.e. NaCl, especially when in water)

Question 16

What are bonds characterized by weak positive zones in an atom that attract the opposite charge with another atom/molecule? (even if the atom is neutral)

Answer 16

Hydrogen Bonds?

Question 17

Why is the structure of water key to life?

Answer 17

Because the hydrogen on a water molecule are on similar sides, this creates a slightly positive and negative zone in the molecule, which allows for various interactions and chemistry to occur. (i.e. H-Bonding). This is the likely reason things dissolve (mainly polar molecules) in H2O, b/c of positive and negative zones.

Question 18

Why don’t lipids dissolve in water?

Answer 18

Positive and negative zones within the lipid molecules cancel each other out, making them neutral and less likely to want to interact with water molecules.

Question 19

What is Hydrophobic?

Answer 19

Molecules that “dislike” water do not dissolve readily in water because of a lack of positive and negative zones.

Question 20

What is Hydrophilic?

Answer 20

Molecules that “like” water and dissolve readily in water because of positive and negative zones.

Question 21

What is the ratio of Hydrogen ions to water molecules in water with a neutral PH of 7?

Answer 21

1 to 10,000,000 (when there is 1 Hydrogen ion for every 10 million H2O molecules, ph is 7)

Question 22

What is the ratio of Hydrogen ions to water molecules in water with a basic PH?

Answer 22

For every 1 Hydrogen molecule, there are greater than 10,000,000 molecules (which makes the ph greater than 7)

Question 23

What is the ratio of Hydrogen ions to water molecules in water with a acidic pH?

Answer 23

When there is greater than 1 Hydrogen molecule for every 10,000,000 water molecules (which makes ph less than 7)

Question 24

What is a substance that maintains a pH at a certain level?

Answer 24

A buffer