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Rina8888 [55]
3 years ago
14

What do astronomers use to calculate the age of the universe? Check all that apply. dark energy the age of rocks on Earth the ag

e of the oldest stars patterns of background radiation how fast distant galaxies are moving away from us
Chemistry
2 answers:
Hitman42 [59]3 years ago
4 0

The answers are:

The age of the oldest stars

How fast distant galaxies are moving away from us

Patterns of background radiation

Using these techniques, and using the Big Bang as reference point, astronomers estimate that the universe may be approximately 12 billion years old.


Likurg_2 [28]3 years ago
4 0

the age of the oldest stars

patterns of background radiation

how fast distant galaxies are moving away from us

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8. Bring the balloon in contact with the wall. What happens to the charges in the wall?
Ne4ueva [31]

When the charged balloon is brought near the wall, it repels some of the negatively charged electrons in that part of the wall. Therefore, that part of the wall is left repelled.

<u>Explanation</u>:  

  • Balloons don't stick to walls. However, if you rub the balloon on an appropriate piece of material such as clothing or a wall, electrons are pulled from the other material to the balloon.
  • The balloon now as more electrons than normal and therefore has an overall negative charge. Two balloons like this will repel each other.
  • The other material now has an overall positive charge. Because opposite charges attract, the balloon will now appear to stick to the other material. If you didn't rub the balloon first, it's charge would be neutral and it wouldn't stick to the wall.
7 0
3 years ago
4NH3 + 5O2-&gt; 4NO + 6H2O<br><br> How many molesof NO are formed if 824g of NH3 react ?
ZanzabumX [31]
824 g NH3 (1 mol/17 g NH3) (4 mol NO/4mol NH3)

48.47 moles NO
4 0
3 years ago
If the half-life of a radioisotope is 10,000 years, the amount remaining after 20,000 years is
Cloud [144]

Answer:

Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.

Explanation:

The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:

Time_________________ Amount

t=0_____________________x

t=10,000 years____________x/2

t=20,000 years___________x/4

During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.

6 0
3 years ago
2. what volume of 0.0150-m hcl solution is required to titrate 150. ml of a 0.0100-m ca(oh)2 solution? (10 points)
laila [671]

100ml volume of  0.0150m hcl solution is requires to titrate 150ml of a 0.0100m caoh2 solution.

Dilution is a solution of decreasing the concentration of a solute in the solution by adding more solvent to the solution. We can use the expression for dilute formula,

    C1 V1 =C2 V2

where C1 is the initial concentration,C2 is the final concentration,V1 is the initial volume and V2 is the final volume. Here given, volume of 0.0150M(C1)  HCL solution is required to titrate 150ml(V2) of a 0.0100M(C1)  Caoh2 solution.

While diluting a solution from a high concentration substance to a low concentration substance we always use the formula of dilution.so, putting all value give  in the expression we get the volume of the final concentration.

          V1=  C2 V2/ C1

               = 0.0100m . 150ml /0.0150M

               = 100ml

The volume of the hcl solution is 100ml.

To learn more about dilution formula please visit:

brainly.com/question/7208939

#SPJ4

3 0
1 year ago
Mitosis occurs during which phase?
lara [203]

Answer:

Prophase

Explanation:

Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes — which were duplicated during S phase — condense and become thousands of times more compact than they were during interphase.

8 0
2 years ago
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