The elements are listed in order of increasing the atomic number. Its the number that is the number of protons in the nucleus of an atom.
Answer:
It is reactive because it has to gain an electron to have a full outermost energy level.
Explanation:
The electron configuration of oxygen is 1s2,2s2 2p4.
Oxygen is in group six in the periodic table so it has six electrons in its valence shell. This means that it needs to gain two electrons to obey the octet rule and have a full outer shell of electrons (eight).
Answer:
The molecular formula of estradiol is:
.
Explanation:
Molar mass of of estradiol = M= 272.37 g/mol
Let the molecular formula of estradiol be 
Percentage of an element in a compound:

Percentage of carbon in estradiol :

x = 18.0
Percentage of hydrogen in estradiol :

y = 24.2 ≈ 24
Percentage of oxygen in estradiol :

z = 2
The molecular formula of estradiol is: 
A homogeneous mixture is made up of multiple different substances. (You can see different parts)
Ex: Cereal in milk or ice in soda
A heterogeneous mixture is a mixture that is mixed well. ( you can’t see the different parts)
Ex: Rain or air
I think it is C. coefficients but I don't know what subscripts are