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jolli1 [7]
3 years ago
7

Pls i need help with this

Chemistry
1 answer:
gregori [183]3 years ago
5 0

Answer:

C

Explanation:

A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.

A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.

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Helpp im timed Part A
aksik [14]

Any deviation in the image of an object when light passing from one medium to other is assciated to the phenomenon of refraction.

<h3>What is refraction ?</h3>

It is the deflection from a straight path undergone by a light ray while passing from one medium (such as air) into another (such as glass) in which its velocity is different.


Basically, the light refraction gives the pencil a slight magnifying effect, which makes the angle appear bigger than it actually is, causing the pencil to look crooked.

<h3 />
  • After Looking at the pencil from the side of a clear glass or resealable plastic bag filled three-fourths with water, we will see the light bends around the pencil, causing it to look bent in the water.

  • When the pencil tilt from side to side, It looks so dramatically broken on looking at it from different angles.
    We can magically “fix” the broken pencil by changing where the pencil is positioned in the glass.

Learn more about Light here;
brainly.com/question/22216162

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3 0
2 years ago
Explain how you would separate a mixture of water, sand, salt and iron filings into its four component parts.
katen-ka-za [31]

You would use the density difference to separate the sand, evaporate the water out (the water vapor will cool back to water if collected). Then use a magnet to get the iron fillings out of the salt.

7 0
3 years ago
If Steve throws a football 57 meters in 3 seconds, what is the average speed of the football?​
sattari [20]

Answer:

19 m/s

Explanation:

57/3

7 0
3 years ago
The matter through which waves travel is called a/an​
sweet [91]

Answer:

A medium.

<h3>Explanation:</h3>

It's the material the wave is travelling through.

5 0
3 years ago
Which statement explains the energy term in this reaction
lana66690 [7]

Answer:

Mass is lost due to the conversion of mass to energy

Explanation:

The question is not complete, the complete question is given as:

        ^{235}_{72}U +^{1}_{0}n                       ⇒        ^{140}_{56}Ba+^{93}_{36}Kr+3^{1}_{0}n+energy

total mass equals 236.053 u              total mass equals 235.868 u

Which statement explains the energy term in this reaction? (1) Mass is gained due to the conversion of mass to energy. (2) Mass is gained due to the conversion of energy to mass. (3) Mass is lost due to the conversion of mass to energy. (4) Mass is lost due to the conversion of energy to mass.

Answer: From Einstein’s equation  E = mc², when a radioisotope element undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass.This mass lost is converted to energy.

The law of conservation of energy  holds for this type of reaction (i.e  the sum of mass and energy is remains the same in a nuclear reaction). Mass changes to energy, but the total amount of mass and energy combined remains the same before and after a nuclear reaction.

From the reaction above, the total decrease in mass = 236.053 - 235.868 = 0.185 u

4 0
3 years ago
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