Question

How are physical and chemical changes similar?

Neither can change the number of atoms of each element that are present.

Neither can cause chemical bonds to break.

Neither can result in a phase change.

Neither can cause a substance to give off heat or light
Need help asap. Pleasee help?

Answer 1

Do you know what physical and chemical change are

Answer 2

Yes

Answer 3

which of the 4 options are not correct

Answer 4

The last one

Answer 5

Yep do you know what a phase change is

Answer 6

no

Answer 7

It is the change in the state of matter (state: solid, liquid Gas)

Answer 8

A) Neither can change the number of atoms of each element that are present.

B) Neither can cause chemical bonds to break.

C) Neither can result in a phase change.

D) Neither can cause a substance to give off heat or light

Answer 9

Oh so it wouldn't be that one either

Answer 10

yep so not C or D

Answer 11

What is B talking about

Answer 12

im not sure

Answer 13

Chemical bonds are the bonds between two atoms in a molecule

Answer 14

Oh I would think it can. I may not be right but im pretty sure the number of atoms in each element stay the same. So I think its A?

Answer 15

yep, in a chemical equation the number of atoms on one side has to equal that on the other and if you melt an ice cube all of the water molecules are still there they are just in a puddle

Answer 16

Oh ok. Well thank you so much!

Answer 17

Could you help me with another question quick?

Answer 18

sure

Answer 19

What must be true for any endothermic reaction?

A) The chemical bonds of the products have more energy than the chemical bonds of the reactants.
B) There are more products than there are reactants.
C) There must be a phase change from solid to liquid or from liquid to gas.
D) The reaction must take place in a sealed container held at constant volume

Answer 20

what is an endothermic reaction

Answer 21

it happens when the system absorbs energy from its surrondings in the form of heat

Answer 22

so it has undergone a chemical reaction in which the products need more energy than they have

Answer 23

C) does it require a phase change?

Answer 24

No?

Answer 25

Have you ever done an experiment where you get an endothermic reaction?

Answer 26

No

Answer 27

You mix two chemicals in a test tube and because it require more energy it pulls in heat causing the bottom of the test tube to go cold.

Answer 28

Is and exothermic reaction a chemical or physical change

Answer 29

Chemical..

Answer 30

yep, C) is a physical change as we said in the previous question

Answer 31

If you have a look at your definition and the question there is an important word that is in one of the answers

Answer 32

Wait wouldn't it be B?

Answer 33

In any reaction there the same number of atoms in the products than there are in the reactants. with B) the excess products won't be used in the reaction and will have no effect on the outcome

Answer 34

Have a look at A

Answer 35

Oh ok so yeah it would have to be A. Right?

Answer 36

wait no sorry i read it wrong

Answer 37

let me reread

Answer 38

Got it

Answer 39

i mixed up my products and reactants

Answer 40

In any reaction there the same number of atoms in the products than there are in the reactants. with B) the excess products won't exist or there will be more in volume or more smaller molecules, still won't effect

Answer 41

Reactants=>Products
Less energy => More energy
do you agree this is what A is saying

Answer 42

Yeah

Answer 43

The products need more energy so they pull is out of their surroundings in the form of heat, causing everything around it to go cold

Answer 44

So, A

Answer 45

Okay thanks again!

Answer 46

Did it make sense or was it confusing?

Answer 47

It actually makes sense....I find this stuff very confusing but surprisingly can understand it when you explain it.

Answer 48

Good, glad i could help