Answer:
A is denser than B as it's volume for the same mass is smaller.
Explanation:
Hello.
In this case, we first need to take into account that the density of each metal A and B is computed by dividing the mass over the volume of each metal which is actually computed by substracting the volume of water from the volume of the water and the solid:

Next, we compute the densities as shown below:

In such a way, A is denser is B as it's volume for the same mass is smaller.
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1) C
2) B
3) A/B not sure
4) C I think
Answer:
D
Explanation:
From periodic table : proton number 19 corresponds to K (potassium)
which is very reactive with water
The difference between an organ and a tissue is that basically tissues are a group of similar cells that works together. Then a group of tissue that works together would make up an organ. Groups of organ working together later makes up an organ system. This is the main difference between an organ and a tissue.