ch 2 test

Question 1

ion

Answer 1

an atom that has gained or lost electrons so that it has a negative or positive charge

Question 2

atomic number

Answer 2

number of protons in an atom

Question 3

chemical bond vs. intermolecular forces

Answer 3

chemical bond
- between atoms
-when atoms share or transfer electrons
-is stronger than intermolecular forces

Intermolecular forces
-between molecules
-happens when opposite forces (positive and negative) attract to each other due to uneven sharing of electrons in the molecule, causing a charge
-weaker than chemical bonds

Question 4

types of chemical bonds

Answer 4

non polar(covalent) - 2 atoms equally share electrons
polar -2 atoms unequally share electrons
ionic - electrons are transferred completely between atoms, and then the opposite forces of the ions attract

Question 5

types of forces

Answer 5

hydrogen bonding - partial charges on one molecule attract to opposite partial charges on another molecule, ( H, O, N, F), between molecules with strong polar bonds
Van der Waal forces - fleeting interactions between moderately polar and nonpolar molecules

Question 6

7 prop of water

Answer 6

1. cohesion - tendancy of the same kind of molecules to stick to each other
2. surface tension - surface of water has a resisitence to being broken
3. adhesion - waters tandancy to stick to other substances
4. boiling and freezing points - large range due to hydrogen bonding
5. specific heat capacity - the amount of energy it requires to raise the heat of something one degree celsius, water is very high
6. density ice is less dense than water so it floats
7. solubility - water can disslove substances that are ionic or polar

these properties happen b/c of polarity which allows for hydrogen bonding

Question 7

acids

Answer 7

release H+ ions into solution when dissloved (low pH)

Question 8

Bases

Answer 8

take up H+ ions out of solution (high pH)

Question 9

Buffers

Answer 9

maintain homeostasis, a weak acid and base that help keep pH change at a minimum

Question 10

carbohydrates

Answer 10

-made of carbon Hydrogen and oxygen (CH2O)
-monomer=monosaccharides
-function=quick energy
-hydrophilic (love water)

Question 11

Lipids

Answer 11

-made of carbon and hydrogen
-monomer=fatty acids and glycerol
-function=store energy and form cell membranes
-hydrophobic (hates water)

Question 12

proteins

Answer 12

-made of amino acids = carbon, amenic group, carboxyl group, side chain
-monomer=amino acid
-function=metobolic functions, enzymes

Question 13

nucleic acids

Answer 13

-made of 5 carbon sugars, phosphate groups, nitrogen bases: admine, thymine, cytothine, guanine,
-monomer=nucleotides
-function=base code for all information stored in cells to make proteins in organism

Question 14

DNA vs. RNA

Answer 14

DNA:
-double strand
-only in nucleus
-entire cell’s code
deoxyribose sugar

RNA:
-single stand
-in nucleus and cytoplasm
-parts of the code
-ribose sugar