answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Annette [7]
2 years ago
7

Which statements describe how stars are born? Check all that apply. Stars are born in clouds of gas and dust called nebulas. The

gas and dust are pulled together by gravity. If the cloud that is pulled together has enough mass, a red giant is formed. The pulled-together cloud collapses and becomes hot and dense. Heat and pressure cause nuclear fusion, which signals the birth of a star.
Chemistry
2 answers:
zhannawk [14.2K]2 years ago
8 0

Answer:

1.Stars are born in clouds of gas and dust called nebulas.

2.The gas and dust are pulled together by gravity.

4.The pulled-together cloud collapses and becomes hot and dense.

5.Heat and pressure cause nuclear fusion, which signals the birth of a star.

Explanation:

prohojiy [21]2 years ago
6 0

Answer: 1.Stars are born in clouds of gas and dust called nebulas.

2.The gas and dust are pulled together by gravity.

3.Heat and pressure cause nuclear fusion, which signals the birth of a star.

Explanation:

You might be interested in
2KOH+H2SO4=k2SO4+2H2O Is a balanced equation, displaying the combination of potassium hydroxide with sulfuric acid increase pota
Lerok [7]

Answer:

The number of moles of potassium hydroxide, KOH required to make 4 moles of K₂SO₄ is 8 moles of KOH

Explanation:

2KOH + H₂SO₄ → K₂SO₄ + 2H₂O

From the above reaction, we have 2 moles of KOH combining with 1 mole of H₂SO₄ to produce 1 mole of K₂SO₄  and 2 moles of H₂O.

Therefore the number of moles of potassium hydroxide that will be needed to make 4 moles of K₂SO₄ is;

8KOH + 4H₂SO₄ → 4K₂SO₄ + 8H₂O

8 moles of KOH is required to make 4 moles of K₂SO₄.

6 0
2 years ago
At 10.°C, 20.g of oxygen gas exerts a pressure of 2.1atm in a rigid, 7.0L cylinder. Assuming ideal behavior, if the temperature
Alja [10]

Answer:

Final pressure = 2.3225 atm

Amontons’s law states that

At constant volume and number of molecules, the pressure of a given mass of gas is directly proportional to its temperature

Explanation:

Temperature causes increased excitement of gas molecules increasing the number of collisions with the walls of the container which is sensed as increase in pressure

Amontons’s law: P/T = Constant at constant V and n

That is P1/T1 = P2/T2

Where temperature is given in Kelvin

Hence T1 of 10°C = 273.15 + 10 = 283.15K

Also temperature T2 of 40°C = 313.15 K

Hence

P2 = (P1/T1)×T2 = (2.1/283.15)×313.15 = 2.3225 atm

3 0
2 years ago
Titration of a 20.0-mL sample of acid rain required 1.7 mL of 0.0811 M NaOH to reach the end point. If we assume that the acidit
Rasek [7]

Answer:

Concentration of sulfuric acid in the acid rain sample is 0.0034467 mol/L.

Explanation:

Volume of NaOH = 1.7 ml = 0.0017 L

Molarity of NaOH = 0.0811 M

Moles of NaOH = n

0.0811 M=\frac{n}{0.0017 L}

n = 0.0001378 mol

H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O

According to reaction, 2 mol of NaOH neutralize 1 mol of sulfuric acid.

Then 0.0001378 mol of NaOH will neutralize:

\frac{1}{2}\times 0.0001378 mol=6.8935\times 10^{-5} mol of sulfuric acid.

Concentration of sulfuric acid in the acid rain sample: x

x=\frac{6.8935\times 10^{-5}}{0.02 L}=0.0034467 mol/L

Concentration of sulfuric acid in the acid rain sample is 0.0034467 mol/L.

7 0
2 years ago
What do you think life on earth would be like if chemistry had not been put to practical use?​
tatyana61 [14]

Answer:

if chemistry hadn't been put up to practical use, we wouldn't truly understand the reason why humans are humans like makes up humans (including other understandings of biology, etc) and we wouldn't be able to have the advancements we have today (vaccines, etc).

Explanation:

5 0
1 year ago
What are the five steps a flavor chemist needs to review before starting a flavor project
Katyanochek1 [597]

Answer:

flavorists, work primarily in the food, beverage, pharmaceutical, cosmetic, and pet industries. They use scientific and analytical tools, along with creativity, to boost natural flavors and create new ones

5 0
2 years ago
Other questions:
  • Which substance can be broken down by chemical means?<br> (1) CO (3) Ca<br> (2) Ce (4) Cu
    9·2 answers
  • why is it less effective to wash an insoluble precipitate with 15 ml of water once than it is to wash the precipitate with 3 ml
    5·1 answer
  • a square boat made from iron has overall dimensions of 2.00 cm x 11.0 cm x 11.0 cm. it has a mass of 213 g. what is its density
    8·2 answers
  • Old photographic flashbulbs burn magnesium metal in a reaction that causes a flash of brilliant white light. A photographer woul
    7·2 answers
  • Write one scientific question about the organism in the photo
    8·2 answers
  • The [H3O+] in a solution is increased to twice the original concentration. Which change could occur in the pH? 2.0 to 4.0 1.7 to
    14·2 answers
  • Avogadro’s number is a constant that helps scientists count atoms and molecules. It is approximately equal to 602,200,000,000,00
    11·2 answers
  • Larisa pumps up a soccer ball until it has a gauge pressure of 61 kilopascals. The volume of the ball is 5.2 liters. The air tem
    15·1 answer
  • A mercury mirror forms inside a test tube as a result of the thermal decomposition of mercury(ii) oxide: 2 hgo(s) → 2 hg(l) + o2
    8·1 answer
  • Compound X has a molar mass of 104.01·gmol−1 and the following composition: element mass % nitrogen 26.93% fluorine 73.07% Write
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!