Plants require pH to thrive which in turn gives us food.
Answer: I think It might be 1 M???
Explanation: Sorry I'm not in high school I put the wrong age
It went under a physical change because it (1) changed color. (2) changed form.
Answer:
The element will be 
Explanation:
Given that,
Number of proton = 80
Number of neutron = 81
Number of electron = 79
We know that,
The atomic number is equal to the number of proton.
So, the atomic number is 80.
According to atomic number,
The element will be mercury.
We need to calculate the atomic mass
Using formula of atomic mass

Put the value into the formula


We need to find the element
Using atomic mass and atomic number


So, the element will be

Put the value of A and Z
Hence, The element will be 