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iVinArrow [24]
3 years ago
8

What existed before the universe

Chemistry
1 answer:
marusya05 [52]3 years ago
6 0
Technically speaking absolutely nothing but from a religious standpoint God did
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Based on the chart, which food chain best models a flow of energy in this ecosystem?
GarryVolchara [31]

Answer:

B

Explanation:

8 0
3 years ago
Semi-conductors have properties of both metals and non metals.which are two examples of metalloids
balu736 [363]
The six metalloids are boron, silicon, germanium, arsenic, antimony, and tellerium.
7 0
3 years ago
Select the correct answer.
Minchanka [31]

Answer:

A.   it is the lowest at low temperatures

Explanation:

It is true with respect to the kinetic energy of a molecule that the it is the lowest at low temperatures.

The kinetic energy of a molecule is the energy due to the motion of the particles within a substance.

  • Kinetic energy is directly proportional to the temperature of a substance.
  • The higher the temperature, the more the kinetic energy of the molecules within a system.
  • At low temperature, kinetic energy is the lowest.
  • At the highest temperature, kinetic energy is the highest
3 0
3 years ago
Read 2 more answers
Which subatomic particle gives off visible light when it drops back down to a lower energy state?
icang [17]

Answer:

Option C = electron

Explanation:

Electrons are responsible for the production of colored light.

Electron:

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol= e-

Mass= 9.10938356×10⁻³¹ Kg

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

How electrons produce the colored light:

Excitation:

When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits.

De-excitation:

When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum.

Other process may involve,

Fluorescence:

In fluorescence the energy is absorbed by the electron having shorter wavelength and high energy usually of U.V region. The process of absorbing the light occur in a very short period of time i.e. 10 ∧-15 sec. During the fluorescence the spin of electron not changed.

The electron is then de-excited by emitting the light in visible and IR region. This process of de-excitation occur in a time period of 10∧-9 sec.

Phosphorescence:

In phosphorescence the electron also goes to the excitation to the higher level by absorbing the U.V radiations. In case of Phosphorescence the transition back to the lower energy level occur very slowly and the spin pf electron also change.

5 0
3 years ago
Suppose there are two known compounds containing the generic elements X and Y. You have a 1.00-g sample of each compound. One sa
Lapatulllka [165]

I think the correct answers are X2Y and X3Y, X2Y5 and X3Y5, and X4Y2 and X3Y, for the following reason: 

If you look at the combining masses of X and Y in each of the two compounds, 

The first compound contains 0.25g of X combined with 0.75g of Y 
so the ratio (by mass) of X to Y = 1 : 3 

The second compound contains 0.33 g of X combined with 0.67 g of Y 
so the ratio (by mass) of X to Y = 1 : 2 

Now, you suppose to prepare each of these two compounds, starting with the same fixed mass of element Y ( I will choose 12g of Y for an easy calculation!) 

The first compound will then contain 4g of X and 12g of Y 
The second compound will then contain 6g of X and 12g of Y 

<span>The ratio which combined the masses of X and the fixed mass (12g) of Y
= 4 : 6 
<span>or 2 : 3 </span>

So, the ratio of MOLES of X which combined with the fixed amount of Y in the two compounds is also = 2 : 3 </span>

The two compounds given with the plausible formula must therefore contain the same ratio.

8 0
3 years ago
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