Question

Help please

Answer 1

A?

Answer 2

@Vocaloid

Answer 3

check your calculations again

(5/2)nRT = (5/2)(3)(8.31)(25+273) = ?

Answer 4

(5/2)(3)(8.31)(25+273) = ?

you just need to chuck this into a calculator ^^

Answer 5

C

Answer 6

good!

Answer 7

C

Answer 8

well done

Answer 9

D

Answer 10

this is a very common mistake but temperature is the measure of avg. molecular velocity, not heat; heat is a measure of thermal energy

Answer 11

so temperature

Answer 12

pressure = Force/Area

since we're talking about the same block, force of gravity is equal, so we are looking for the smallest surface area of the side

Answer 13

c

Answer 14

9 * 3 = 27 but there's a smaller one than that

Answer 15

B

Answer 16

good, B

Answer 17

you're given A1, F1, and A2, just need to plug in and solve for F2

F1/A1 = F2/A2

2500/0.06 = F2/0.18 solve for F2

Answer 18

a

Answer 19

good

Answer 20

d

Answer 21

good

Answer 22

B

Answer 23

good

Answer 24

B

Answer 25

good

Answer 26

either a or b

Answer 27

well we determined earlier that Archimedes' principle states that buoyant force is proportional to volume (so A not B)

Answer 28

D

Answer 29

yeah good

Answer 30

B

Answer 31

water molecules are very attracted to each other causing them to bond together on surfaces, resulting in high surface tension not low

as a hint, water has a high heat capacity which would result in which answer choice as the correct conclusion?

Answer 32

A

Answer 33

recall that a high heat capacity means that water must take in a lot of heat to change its temperature, the opposite of what A is stating

Answer 34

uugh um d

Answer 35

good, D

Answer 36

Ugh stuck between b and d

Answer 37

B would be cohesion (being attracted to itself), D would be adhesion (attraction to other surfaces), so D

Answer 38

B

Answer 39

good

Answer 40

B

Answer 41

good

Answer 42

well let's start with in nucleus vs. out, there are two particles that are in and one type that is out, what are they?

Answer 43

Actually I did it, can you just check it over

Answer 44

good but you missed "smallest" which particle is this?

Answer 45

oh wait you put it under electron never mind yeah that's right

Answer 46

No i didnt

Answer 47

smallest would be electron right?

Answer 48

yeah good

Answer 49

Compare the numbers of protons and electrons in a positive ion with the numbers of protons and electrons in a negative ion.

Answer 50

well if it's positive which is greater, # protons or # electrons?

Answer 51

protons

Answer 52

good, so positive ion would be "more protons than electrons" and then for negative ion it would just be the opposite, "more electrons than protons" that's really it

Answer 53

How many protons, neutrons, and electrons does a neutral atom of nitrogen-15 have

Answer 54

well, # of protons is easy --> just look at the ptable and find its atomic number

Answer 55

ptable.com atomic number is 7, then the number of electrons is also equal to protons since the atom is neutral, then to find neutrons just subtract mass # (15) - atomic number (7)

Answer 56

A nitrogen atom has 7 protons, typically 7 neutrons, and 7 electron

Answer 57

you're on the right track but we are talking about nitrogen-15 which is not a typical nitrogen atom

Answer 58

# of neutrons = mass # - atomic # = 15 - 7 = ?

Answer 59

8

Answer 60

good so 7 protons ; 7 electrons ; 8 neutrons

Answer 61

Many scientists have contributed to the atomic theory. Match the scientists below with the correct descriptions of their work. Some scientists will be used more than once. (1 point)

A. Thomson
B. Bohr
C. Rutherford
D. Dalton



_____ Believed that electrons move in specific orbits

_____ Discovered electrons

_____ Believed that atoms could not be broken into smaller parts

_____ Experimented with cathode rays

_____ Inferred that atoms have a small, dense, positive nucleus

_____ Developed plum-pudding model

_____ Shot particles at gold foil

Answer 62

Well the last two are c and a

Answer 63

yeah, that's good, for this one you really just have to look them up

ex. electrons in orbits would be Bohr

Answer 64

lmk if you're getting stuck or need help

Answer 65

__B___ Believed that electrons move in specific orbits

__A___ Discovered electrons

__D___ Believed that atoms could not be broken into smaller parts

___A__ Experimented with cathode rays

_____ Inferred that atoms have a small, dense, positive nucleus

___C__ Developed plum-pudding model

__A___ Shot particles at gold foil

Answer 66

you mixed up the last two, rutherford was the one with the gold foil and thompson was the one who came up w/ the plum pudding model

Answer 67

"Inferred that atoms have a small, dense, positive nucleus"

hint - this was a result of the gold foil experiment

Answer 68

C

Answer 69

good, so

__B___ Believed that electrons move in specific orbits

__A___ Discovered electrons

__D___ Believed that atoms could not be broken into smaller parts

___A__ Experimented with cathode rays

__C__ Inferred that atoms have a small, dense, positive nucleus

___A__ Developed plum-pudding model

__C___ Shot particles at gold foil

Answer 70

Explain the progression of ideas from a variety of scientists that led to the current understanding of atomic theory.

Answer 71

this is a very bare-bones and I would recommend fleshing this out but:

Dalton, used ideas about the atoms from the Greeks (particularly Aristotle), thought atoms were indivisible, every atom in a particular element is identical in composition

JJ Thompson - plum pudding, cathode ray experiments, discovered charge of electron

Rutherford - gold foil, model where atom had dense center w/ mostly empty space outside the center

Bohr - came up w/ orbit model and the idea of quantized electron energy, positions of electrons could only be on integer energy levels

Schrodinger: quantum atom model where electrons are de-localized in electron clouds instead of orbits

Answer 72

I would try to put this into coherent sentences, make sure to fill in approximate dates, do any additional clarification/research to help explain certain things in more detail, etc.

Answer 73

Each person should probably have its own short 2-5 sentence paragraph

Answer 74

did that, i added more details and dates.

Answer 75

hoose one example from the historical development of the atomic theory, and use it to illustrate how models are used in the process of forming conclusions from scientific experiments.

Answer 76

well, I think the Rutherford gold experiments are good example - since he wanted to test a hypothesis about the structure of the atom, had very unexpected results (the atom had a dense center that reflected particles), and had to come up with a better model to describe his results, which is an example of how he used a model to form a conclusion about the structure of the atom

Answer 77

something like that

Answer 78

I got the idea let me reword it :)

Answer 79

I am not sure about the phrasing for a) but it seems like they want you to color three regions not just three elements, the metal, nonmetal, and metalloid regions (just have to look up a periodic table and color the areas)

Answer 80

for b) full valence shells => last group, where helium and the noble gases are

Answer 81

okay and c

Answer 82

I can't see below where it says "sort the descriptions below"

Answer 83

Atoms can bond in several different ways. Sort the descriptions below into the three types of chemical bonding.

Answer 84

may I see the descriptions please

Answer 85

do you have any guesses/ any ideas where to start?

Answer 86

like, for "two atoms share electrons" do you remember which one this is?

Answer 87

covalent

Answer 88

good, what about 'two oppositely charged ions"?

Answer 89

ionic

Answer 90

good, what about metal + nonmetal?

Answer 91

you kinda just have to memorize this, it's ionic

Answer 92

any ideas for "delocalized electrons + positive ions"?

Answer 93

metallic

Answer 94

good

two nonmetals -->?

Answer 95

ionic

Answer 96

nonmetals form covalent bonds w/ each other (just have to memorize this)

Answer 97

electron transfer between atoms -->?

Answer 98

metallic

Answer 99

close but not quite

when ions are formed, they gain/lose electrons, right? and when ions bond w/ each other, electrons are transferred from the anion to the cation---> making ionic the better answer

Answer 100

that leads us into d) ---> metals lose electrons, and if a neutral metal loses electrons is the new charge positive or negative?

Answer 101

neg

Answer 102

electrons are negative charge

so if the negative charges are going away, what's the charge of the remaining atom?

Answer 103

positove

Answer 104

good, that's it for d

Answer 105

When you hold a rectangular object, how does the area of the side that is resting on your hand affect the pressure and the force that the object exerts

Answer 106

P = F/A, force of gravity is constant for an object, so the area determines pressure

Answer 107

this is the answer right, there wouldn't be any numbers

Answer 108

yeah, we aren't given any numbers so we can't do any calculations

Answer 109

What are four types of energy that might make up the internal energy of a substance?

Answer 110

internal

Answer 111

heat
chemical

Answer 112

I'm not 100% sure what they want as the answer here but I'd say translational kinetic energy, vibrational KE, rotational KE, potential energy from intermolecular forces

Answer 113

Yeah i wasn't sure either the question is very vague

Answer 114

(I don't know whether they want you to consider the macroscopic vs microscopic perspective)

Answer 115

anyway I should probably sleep I have an 8am tomorrow goodnight

Answer 116

See ya