All categories

3 years ago

Which statement gives a reason why scientist think that the universe began with an explosion

Chemistry

1 answer:

yaroslaw [1]3 years ago

8 0

I believe the answer is

At the moment it is the best way of explaining our scientific knowledge.

You might be interested in

Almost 99% of the Earth's atmosphere is made up of two gases. What ere the two gases and the percents of each?

Gwar [14]

Answer:

21% oxygen and 78%nitrogen

Explanation:

6 0

3 years ago

Read 2 more answers

Which of the following leads to a higher rate of diffusion?

miv72 [106K]

<h3>Answer;</h3>

Higher velocity of particles

<h3>Explanation;</h3>

The diffusion rate is determined by a variety of factors which includes;

Temperature such that the higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly and the diffusion rate will be high.
Concentration gradient such that the greater the difference in concentration, the quicker the rate of diffusion.
Higher velocity of particles increases the diffusion rate as this means more kinetic energy by the particles and hence the particles will mix and move faster, thus higher diffusion rate.

5 0

3 years ago

The table shows the average distance between the molecules of a substance in the solid, liquid, and gaseous states.

Pavlova-9 [17]

Answer:

Y > X > Z

Explanation:

The intermoecular forces refer to forces that exist between molecules of a substance. They are the secondary bond forces that hold particles of a substance together in a particular state of matter.

The shorter the distance between molecules, the greater the magnitude of intermolecular force between the molecules.

The molecules of Y are at the shortest distance from each other hence they have the highest magnitude of intermolecular forces. Followed by X and lastly Z with the greatest distance between the largest intermolecular distance.

7 0

3 years ago

Solve fasttt C7H17+O2=CO2+H2O Balancing Equations

sertanlavr [38]

Answer:

The answer to your question is

4C₇H₁₇ + 45 O₂ ⇒ 28 CO₂ + 34H₂O

Explanation:

Write the equation

C₇H₁₇ + O₂ ⇒ CO₂ + H₂O

Process

1.- Check if the equation is balanced

Reactants Element Products

7 C 1

17 H 2

2 O 3

As the number of reactants and products is different, we conclude that the reaction is unbalanced.

2.- Write a coefficient "7" to CO₂ and a coefficient of 17/2 to H₂O

C₇H₁₇ + O₂ ⇒ 7CO₂ + $\frac{17}{2}$ H₂O

Reactants Element Products

7 C 7

17 H 17

2 O 51/2

3.- Write a coefficient of 45/2 to the O₂, and multiply all the equation by 2.

4C₇H₁₇ + 45 O₂ ⇒ 28 CO₂ + 34H₂O

Reactants Element Products

28 C 28

68 H 68

90 O 90

5 0

3 years ago

Which liquid has the highest vapor pressure at 75°C?

Temka [501]

Answer:

1) Ethanol

Explanation:

If we will have interactions we will need more energy to break them in order to go from liquid to gas. If we need more energy, therefore, the temperature will be higher.

In this case, we can discard the propanone because this molecule don't have the ability to form hydrogen bonds. (Let's remember that to have hydrogen bonds we need to have a hydrogen bond to a heteroatom, O, N, P or S).

Then we have to analyze the hydrogen bonds formed in the other molecules. For ethanol, we will have only 1 hydrogen bond. For water and ethanoic acid, we will have 2 hydrogen bonds, therefore, we can discard the ethanol.

For ethanoic acid, we have 2 intramolecular hydrogen bonds. For water we have 2 intermolecular hydrogen bonds, therefore, the strongest interaction will be in the ethanoic acid.

The closer boiling point to the 75ºC is the ethanol (boiling point of 78.8 ºC) therefore these molecules would have enough energy to break the hydrogen bonds and to past from liquid to gas.

4 0

3 years ago