Answer:
The answer is A. Polar covalent; negatively
Explanation:
Hydrogen bonds form between molecules containing polar covalent bond the hydrogen bond is been a hydrogen atom of one molecule and a partially negative charged atom of another.
Example
(water):- It contain a slight positive charge on one side and a slight negative charge on the other.
Answer:
your question is incomplete and its

particles which is one mole of a substance
Explanation:
you can solve the question by using this formular 1 mole of a substance=mass of the substance/ its molar mass
you find molar mass of a compound by adding individual molar masses of elements in that compound
Answer:
add 7.5L of water
Explanation:
M1×V1=M2×V2
M is molarity, V is volume
0.7 × 10 = 0.4 × V2
V2= 17.5L
vol. of water to add= 17.5 - 10 = 7.5L
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: 