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Marrrta [24]
4 years ago
8

How do scientists know that the universe is expanding? Question 2 options: a) The Doppler effect shows stars with red shifted li

ght. b) The Doppler effect shows stars with blue shifted light. c)The Doppler effect shows stars with green shifted light. d)The Doppler effect shows stars with yellow shifted light.
Chemistry
1 answer:
Vsevolod [243]4 years ago
3 0
The answer is A, which is often known as the red shift. It is the displacement of spectral lines toward longer wavelengths.
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How many grams of NaOH are produced from 1.20 x 10^2 of Na2O
oksian1 [2.3K]
Write an balance the equation

Na2O + H2O -> 2 NaOH

Calculate the molecular mass of Na2O and NaOH from the atomic mass from the periodic table.

Na = 23
O=16
H=1

Na2O = 23 * 2 + 16 = 62
NaOH = 23+16+1= 40

For the stoichiometry of the reaction one mole of Na2O = 62g produce two mol of NaOH = 2* 40= 80 g

120 g Na2O x 80g NaOH / 62g Na2O=

154.8 g NaOH
5 0
4 years ago
What color is the start of the rainbow?
zheka24 [161]

Rainbows go in the order of ROYGBIV, which is an acronym for red, orange, yellow, green, blue, indigo, violet.

So, it would start off with red.

If you want to know why it starts off the rainbow, its because red has the longest wavelength, compared to the rest of the colors. (sorry I'm rambling, I got excited)

Hope this helps.

4 0
4 years ago
Look at the image below:
PIT_PIT [208]

Answer:

The figure is a molecule and a compound

Explanation:

Because it have 2 cluster molecules

7 0
3 years ago
If one body is positively charged and another one is negatively charged free electrons tend to ?
lord [1]

Answer is: Move from the negatively charged body to the positively charged body.

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The proton (p⁺) is subatomic particle with a positive electric charge of +1e elementary charge.

Opposite charges (positive and negative) attract one another.  

The negatively charged body has extra electrons, more electrons than protons.

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5 0
4 years ago
Read 2 more answers
How do scientists know how atoms are structured?
astraxan [27]

Explanation:

i guess it's through thousands of research and experiments they conducted

5 0
3 years ago
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