In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. Hope this helps!
Answer:

Explanation:
1. Take in account the sulfuric acid at STP:

2. Density is expressed as the ratio between the mass and the volume of a substance so:

Solving for m:

3. Replace values:


<span>Okay then I would go with choice B since fusion takes place in the sun which is a giant star.</span>
Answer:
- <em><u>Step 2 (the slow step).</u></em>
Explanation:
The rate-determining step is always the slow step of a mechanism.
That is so, because it is the slow step which limits the reaction.
Imaging that for assembling a toy you have process of three steps:
- 1. order ten pieces, which you can do in 1 minute: meaning that you can order order the pieces for 60/1 = 60 toys in 1 hour.
- 2. glue the pieces and hold the toy until the glue hardens, which takes 1 hour: meaning finishingh 1 toy in 1 hour.
- 3. pack the toy, which takes 2 minutes: meaning that you can pack 60/2 = 30 toys in one hour.
The time to glue and hold one toy until the glue hardens determines that you can assemble 1 toy in 1 hour and not 60 toys or 30 toys.
Thus, the step that determines the rate at which the reaction happens is the slowest step: step 2.
For the same amount of energy, the number of photons in red light will be greater than the number of photons in blue light.
This is because the energy carried by a photon is inversely proportional to the wavelength of the photon. A longer wavelength means there is a lower energy in the photons and a shorter wavelength means that there is a higher energy. Therefore, in order for the photons to deliver one joule of energy, more of the red light photons will be required.