90 elements occur naturally on earth.
Answer:
C 1:1
Explanation:
Hydrogen loses an electron to becone +1 which is a cation and flourine gains that electron to have a full outer shell on the 2p subshell to become -1 and is an anion so the ratio is 1:1.
Answer:
Im sorry i though this was a joke i don't know I'm sorry:
Answer:
True
Explanation:
The physical changes are reversible in most cases and these changes are not the chemical changes which means that it is only the change in its state not in their nature. Just take the example of water, on cooling it becomes solid and change in color can be seen which is white in solid form and colorless in liquid form. This is also reversible and is a physical change. This means that physical changes can be identified at macroscopic level. Hence the answer is true.
