bio 2

Question 1

matter is made up of ___

Answer 1

elements

Question 2

elements are fundamental forms of ____

Answer 2

matter

Question 3

symbol for hydrogen

Answer 3

H

Question 4

symbol for calcium

Answer 4

Ca

Question 5

Symbol for potassium

Answer 5

K

Question 6

symbol for phosphorous

Answer 6

P

Question 7

symbol for Iron

Answer 7

Fe

Question 8

how many elements are essential to people?

Answer 8

25

Question 9

how many elements make up 96% of the weight of the body and what are they?

Answer 9

oxygen
carbon
hydrogen
nitrogen

Question 10

what are the elements called that are required in only small amounts but are still essential? give and example of one

Answer 10

trace elements
fluorine

Question 11

define a compound

Answer 11

a substance consistion of two or more different elements in a fixed ratio

Question 12

a compound has characteristics different then those of _____ alone

Answer 12

elements

Question 13

what kind of particles are atoms composed of?

Answer 13

subatomic

Question 14

what are the three relevant subatomic particles?

Answer 14

neutrons
protons
electrons

Question 15

what do neutrons and protons form?

Answer 15

the atomic nucleus

Question 16

what do electrons form?

Answer 16

cloud around the nucleus

Question 17

what is an atomic number?

Answer 17

number of protons in a nucleus

Question 18

what is a mass number?

Answer 18

the sum of protons plus neutrons in the nucleus

Question 19

what is atomic mass?

Answer 19

the atoms total mass

Question 20

all atoms of an elements have the same number of ___ but differ on number of ____

Answer 20

protons
neutrons

Question 21

what are isotopes?

Answer 21

two atoms of an element that differ in number of neutrons

Question 22

what happens when an isotope breaks down?

Answer 22

it gives off lots of energy

Question 23

protons determine the ____

Answer 23

element

Question 24

neutrons determine the_____

Answer 24

isotope

Question 25

electrons determine _____

Answer 25

chemical behaviour

Question 26

what are valence electrons?

Answer 26

electrons in the outermost shell

Question 27

what can atoms with incomplete valence shells share?

Answer 27

valence electrons with certian atoms

Question 28

three kinds of chemical bonds

Answer 28

covalent ionic hydrogen

Question 29

what is a covalent bond

Answer 29

the sharing of a pair of valence electrons by two atoms

Question 30

in a covalent bond, the shared _____ count as part of each atoms valence shell

Answer 30

Electrons

Question 31

what is it called when there is an equal sharing of electrons by two hydrogen atoms?

Answer 31

non polar covalent bond

Question 32

in a polar covalent bond, one atom is more ____ and the atoms do not share the electron equally

Answer 32

electronegative

Question 33

what does unequal sharing of electrons cause?

Answer 33

partial positive of negative charge for each atom or molecule

Question 34

what is an ionic bond?

Answer 34

atoms may strip electrons from their bonding partners

Question 35

what happens when an electron is transferred?

Answer 35

both atoms have charges

Question 36

what is a charged atom called?

Answer 36

an ion

Question 37

what is a hydrogen bond?

Answer 37

a slightly positive end of one polar molecule attracts the negative end of another polar molecule

Question 38

define chemical reactions

Answer 38

the making and breaking of chemical bonds

Question 39

although cells are 70-95% water, the rest consists mostly of ____ ____ compounds

Answer 39

carbon based

Question 40

what is organic chemistry?

Answer 40

the study of compounds that contain carbon

Question 41

carbon most frequently partners with what three elements?

Answer 41

hydrogn oxygen nitrogen