chapter4-basic food chemistry

Question 1

What part does protons and neutrons are same as each other?

Answer 1

mass

Question 2

how much weight is e-?

Answer 2

1836 e- =one proton

Question 3

how e- prefer to move?

Answer 3

in pairs

Question 4

how many elements naturally and scientists create?

Answer 4

90

27

Question 5

what determine which element an atom is?

Answer 5

number of protons

Question 6

who develop the periodic table?

Answer 6

Russian chemist- Dmitry Mendeleyev

Question 7

what is AMU? what is one AMU?

Answer 7

atomic mass unit- mass of a proton or neutron

Question 8

not all atoms of an element have the same number of neutrons. T/F

Answer 8

true

Question 9

what are columns called?

Answer 9

groups 18

Question 10

what are rows called?

Answer 10

periods 7

Question 11

how does metal usually look like? except for?

Answer 11

solid in rtp.

Mercury-liquid in rtp.

Question 12

what are metals good at?

Answer 12

conduct heat and electricity.

Question 13

how does half of non metals look like?

Answer 13

gas in rtp. brittle易碎 when solid.

Question 14

what does chemical formula represent?

Answer 14

one molecule or unit of a compound.

Question 15

what is structural formula?

Answer 15

show the arrangement of the atoms in the molecule.

Question 16

what is chemical bond?

Answer 16

force hold 2 atoms together

Question 17

what are shells refers to?

Answer 17

energy level or their principle quantum number.

Question 18

how is stable element likely to form chemical bond?

Answer 18

least likely

Question 19

what is ionic bond?

Answer 19

e- are transfer from one atom to another, cause both atoms have a charge.

Question 20

what is ionic bond result of?

Answer 20

attraction between a + and - charge. e.g. NaCl

Question 21

what causes a crystalline?

Answer 21

the regular arrangement of atoms–the result of interaction between - and
+ ions.

Question 22

what happen after Na ions push away Na and towards to Cl?

Answer 22

cause sodium and chlorine atoms form an alternating pattern or structure.

Question 23

why ionic bonds tend to disslove in water?

Answer 23

one end of water molecule slightly +, the other side is slightly -

Question 24

where is ionic bond form?

Answer 24

between metal and non metal.

Question 25

what can KCl do?

Answer 25

no-salt seasonings调味品

Question 26

what can CaCl do?

Answer 26

as drying agent

Question 27

water molecule are formed by covalent bond or ionic bond?

Answer 27

covalent bond

Question 28

who develop lewis structure?

Answer 28

Gilbert Newton Lewis- US chemist

Question 29

how matter can be classification?

Answer 29

pure substance and mixtures

Question 30

how pure substance can be classification?

Answer 30

compounds and elements

Question 31

how compound can be classification?

Answer 31

organic and inorganic

Question 32

how mixture can be classification?

Answer 32

homogeneous and heterogeneous

Question 33

which 3 elements are important and good health in food science?

Answer 33

iron, calcium, zinc

Question 34

what does most organic compounds have?

Answer 34

chains or rings of carbon.

hydrogen and oxygen

Question 35

all source of energy in diet is organic/inorganic?

Answer 35

organic

Question 36

Is milk a mixture or compound?

Answer 36

mixture

Question 37

what is solution?

Answer 37

homogeneous mixture of one material dissolved in another.

Question 38

how can substances in heterogeneous mixtures be separated?

Answer 38

mechanical means

Question 39

what does solid have?

Answer 39

definite shape and volume

Question 40

is phase change reversible?

Answer 40

yes.

Question 41

what is the difference between fluid and non-newtonian fluids?

Answer 41

fluids: liquid and gas

non-newtonian fluids:liquid and solid. –>面粉团 玉米糊 比较难移动

Question 42

what is chemical change example?

Answer 42

browning when toasted bread.
mix water and baking powder.
fermenting grape.
release gas, odor, color and flavor change.

Question 43

what is a reversible chemical change?

Answer 43

the way your body use food