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Trava [24]
3 years ago
9

State whether the following is an example of a physical or chemical change:! 21. Burning a log: ________________________________

! 22. Folding a piece of paper: _________________________! 23. Freezing water: _________________________! 24. Bending a copper wire. _________________________!
Chemistry
2 answers:
lyudmila [28]3 years ago
6 0

Answer:

Physical change

Explanation:

Because it doesn't require any chemical to change

Ivan3 years ago
5 0

Answer:

Physical change

Physical change

Physical change

Physical change

Explanation:

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Which identifies an oxidation-reduction reaction?
Alchen [17]

The statement that identifies an oxidation-reduction reaction is a reaction in which oxidation numbers change (option C).

<h3>What is a redox reaction?</h3>

A redox or oxidation-reduction reaction is a chemical reaction in which some of the atoms have their oxidation number changed.

In a chemical reaction that involves oxidation and reduction, the oxidation number of the involved ions either decreases or increases.

Therefore, the statement that identifies an oxidation-reduction reaction is a reaction in which oxidation numbers change.

Learn more about redox reaction at: brainly.com/question/13293425

#SPJ1

6 0
1 year ago
If the valency of oxygen is 2, derive the valencies of the other elements present in the following oxides. Na2O, ZnO , Al2O3 , M
11Alexandr11 [23.1K]

Answer:

1)Na2O

let the valency of Na is x

2(x)+(2)=0

2x+2=0

2x=-2

x=-1

2)ZnO

let the valency of Zn is x

x+2=0

x=-2

3)Al2O3

let the valency of Al is x

2(x)+3(2)=0

2x+6=0

2x=-6

x=-3

4)MgO

let the valency of Mg is x

x+2=0

x=-2

7 0
3 years ago
Read 2 more answers
Transferring or sharing electrons between atoms forms
3241004551 [841]
It forms something called a bond.
4 0
3 years ago
During which two minutes time period is the temperature of water changing faster?!
Vlad1618 [11]

Answer:

2-4 minutes

Explanation:

Fastest changing temperature means larger change in temperature when subtracting final temperature from initial temperature in a given time period (given time period is 2 minutes for all the options)

For 0-2 minutes, our final temperature was 40 (at 2 min) and initial temperature was  20 (at 0 min), thus temperature change was only 20 C.

For 2-4, our final temperature was 80 (at 4 min) and initial temperature was   40 (at 2 min) thus temperature change was 40 C.

For 4-6, our final temperature was 100 (at 6 min) and initial temperature was   80 (at 4 min) thus temperature change was 20 C.

We are not given temperature at 8 min so option D is invalid.

As we can clearly see that in a given 2 minute period, option B has the fastest change because it changed 40C when compared to other options that changed only 20C from starting temperature.

Hope that makes sense.

4 0
1 year ago
Which theory describes the motion of and force driving earth’s plates?
swat32

The theory that describes the motion and force driving earth's plates is Plate tectonics

Explanation:

Plate tectonics states that the outer shell of the Earth is divided into plates that glide and move over the mantle which is the surface of the earth.

The mantle is the rocky inner layer above the core of the Earth.

Plate tectonics helped the geologists to explain how continents could move around the planet.

There are 9 major plate tectonics , namely North American, Pacific, Eurasian, Australian, African, Indo - Australian,Indian South American and Antarctic. These plates have been named after the land form found on them.

7 0
2 years ago
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