Answer:
I believe the answer is A.
Explanation:
This section states that protozoa live in all bodies of water therefore B can not be an answer because it says protozoa dose not live in any body of water.
I hope this answers your question.
It is possible to use a flame test to detect the presence of an alkali metal ion. A cleaned, moistened flame test wire is dipped into a solid sample of the compound. It is then put into the edge of a blue Bunsen flame. The flame colour produced indicates which alkali metal ion is present in the compound.
Hope it works plz mark me as brainliest
Uhhh pretty sure B
Happy New Years
It has 49 electrons as well. The amount of protons and electrons are equal.
Answer: 69.72 kg of cryolite will be produced.
Explanation:
The balanced chemical equation is:

To calculate the moles, we use the equation:

moles of
= 
moles of
= 
moles of
= 
As 1 mole of
reacts with 6 moles of 
166 moles of
reacts with =
moles of 
As 1 mole of
reacts with 12 moles of 
166 moles of
reacts with =
moles of 
Thus
is the limiting reagent.
As 1 mole of
produces = 2 moles of cryolite
166 moles of
reacts with =
moles of cryolite
Mass of cryolite
= 
Thus 69.72 kg of cryolite will be produced.