science term 1 - chemistry

Question 1

What is the atomic number represent?

Answer 1

Number of protons in the nucleus

Question 2

what does the atomic mass represent?

Answer 2

total number of protons and neutrons in the nucleus

Question 3

what charge do protons have?

Answer 3

positive charge

Question 4

what charge do electrons have?

Answer 4

negative charge

Question 5

atoms have a solid, massive (contains mass) nucleus in the centre that contains…

Answer 5

protons and neutrons

Question 6

electrons orbit the…

Answer 6

nucleus

Question 7

what can atoms do to get a full outermost shell?

Answer 7

atoms can take or give away electrons to gain a full outermost shell.

Question 8

what does an atom become when it gives away or takes electrons from other atoms?

Answer 8

it becomes an ion

Question 9

do metals like to give away or take electrons

Answer 9

they like to give them away

Question 10

do non-metals like to give away or take electrons

Answer 10

they like to take them

Question 11

what charge does a neutron have

Answer 11

neutrons do not have a charge (they have a neutral charge)

Question 12

what is a polyatomic ion aka “radicals” ?

Answer 12

an ion composed of more than one element

Question 13

how can you tell if something is a polyatomic ion?

Answer 13

if it has more than one capital letter in it, and a charge, it is a polyatomic ion

Question 14

what happens during a chemical reactions/ what is a chemical reaction?

Answer 14

during a chemical reaction elements break apart and recombine in different ways to form new substances

Question 15

what are the signs of a chemical reaction

Answer 15

• Effervescence (bubbling/fizzing)
  
  • Colour change
  • Smell/taste change (never test in a lab)
  • Temperature change

Question 16

what is a covalent compound

Answer 16

2 or more non-metals that are bonded together

Question 17

how do covalent compounds form?

Answer 17

they are formed when 2 or more non-metals are bonded together

Question 18

what happens when covalent compounds form

Answer 18

when they form, they atoms share the electrons in the outermost shells. because of this, the bonds between the atoms are weaker, and the atoms can combine together in different ratios

Question 19

in covalent compounds, what do we use to describe the number of each element in a formula

Answer 19

we use prefixes (eg. mon…, di…, tri…, tetra…)

Question 20

what is H²O

Answer 20

water

Question 21

what is CH⁴

Answer 21

methane

Question 22

what is NH³

Answer 22

ammonia

Question 23

what is C⁶H¹²O⁶

Answer 23

glucose

Question 24

what is an isotope

Answer 24

Isotopes are the alternative forms of an atom element that have a different number of neutrons to that found in a typical atom of that element

Question 25

what is the common isotope for carbon

Answer 25

Carbon 14, C¹⁴

Question 26

how many extra neutrons does Carbon 14, C¹⁴ have than the regular carbon atom (carbon 12)

Answer 26

2 extra neutrons than the regular carbon atom

Question 27

What is the isotope for uranium 238 (238 = regular atomic mass)

Answer 27

Uranium 235

Question 28

How many neutrons in uranium 235 (92 protons)

Answer 28

143 neutrons

Question 29

what is the role of a neutron

Answer 29

to make the atom stable

Question 30

How many neutrons in uranium 238 (92 protons)

Answer 30

146 neutrons

Question 31

is uranium 238 an isotope or the regular uranium atom

Answer 31

it is the regular uranium atom

Question 32

what can unstable nuclei do to become more stable

Answer 32

eject particles out of themselves OR rearrange themselves

Question 33

what is the largest type of radiation

Answer 33

alpha α

Question 34

what is the type of radiation that happens when a neutron turns into a proton

Answer 34

beta β

Question 35

what is the type of radiation that occurs when the protons and neutrons rearrange themselves.

Answer 35

gamma γ

Question 36

what is the mass of an alpha (α) particle

Answer 36

4

Question 37

how many protons does an alpha (α) particle contain

Answer 37

2

Question 38

what happens when an atom undergoes beta decay

Answer 38

a neutron in its nucleus turns into a proton

Question 39

what is the mass of a beta particle

Answer 39

beta particles do not have a mass

Question 40

how much do beta particles increase the atomic number by

Answer 40

1

Question 41

what happens when gamma (γ) radiation is emitted

Answer 41

the protons and neutrons in the nucleus shuffle around and rearrange themselves

Question 42

does the total number of each particle change in gamma (γ) radiation

Answer 42

no

Question 43

what is the mass of one proton

Answer 43

1 amu

Question 44

what is the mass of one neutron

Answer 44

1 amu

Question 45

what is the mass of one electron

Answer 45

0 amu

Question 46

what does 'amu' stand for

Answer 46

atomic mass unit

Question 47

what is the definition of a half-life

Answer 47

the period of time it takes for half of whatever mass existed at the start of that life to break down

Question 48

if you start with 1000g uranium and after one half life (pretend one half life is 20 mins for now) you have 500g. how many grams will you have after the second half life?

Answer 48

250 g

Question 49

what gas is the "pop test" used to test for

Answer 49

hydrogen

Question 50

when performing the 'pop test' to test for hydrogen, how do you know if hydrogen is present.

Answer 50

you will hear a high pitched "whine"/"pop"

Question 51

what test to you do to test for carbon dioxide

Answer 51

a "limewater" test

Question 52

when performing a "limewater" test, how do you know if carbon dioxide is present

Answer 52

the carbon dioxide will turn the lime water green

Question 53

what gas is a "limewater" test used to test for

Answer 53

carbon dioxide

Question 54

what gas is a "glowing splint" test used to test for

Answer 54

oxygen

Question 55

what test is used to test for oxygen

Answer 55

a "glowing splint" test

Question 56

what type of radiation penetrates (travels) the shortest distance

Answer 56

alpha radiation α

Question 57

which type of radiation penetrates the furthest

Answer 57

gamma radiation