1) B, Not 100% sure though

2)Building a rocket is a physical change technically its not changing its composition its just changing its appearance, the fuel for it causes a chemical change, there is an answer that is more clear, Grinding chalk into a fine powder only changes its shape which is a physical change.

4 0

4 years ago

HELP ASAP 20 POINTS

Colt1911 [192]

Solubility of a compound in water can be referred to as the amount of the compound that can be dissolved in 1 L of the solvent (water) at any given temperature. Solubility of a compound can be expressed in the units of g/L or mg/L.

Given that the solubility of calcium carbonate in water = 14 mg/L

We have to calculate the volume of water that can dissolve 11 g of calcium carbonate.

Converting 11 g calcium carbonate to mg:

$11g *\frac{1000mg}{1g} =11,000 mg$

Volume of water that would dissolve 11000 mg calcium carbonate

= $11000 mg CaCO_{3}*\frac{1L}{14 mg}$

=785.7 L

Rounding the volume 785.7 L to two significant figures, we get 790 L water.

Therefore, we would need 790 L water to completely dissolve 11 g of calcium carbonate.

4 0

3 years ago

How would you explain the close similarities between

PolarNik [594]

<span>They have similar or common ancestor. The similarities inherited from the common ancestor as in the case of homologous organs. In evolutionary biology a group of organisms share a common descent if they have a common ancestor. There are many other examples like in the case of hemoglobin to prove the theory of common ancestor</span>

4 0

4 years ago