A covalent bond is the bond formed by the sharing of a pair of electrons by two atoms.
Your answer is D: A bond between two atoms.
Answer:
The reaction in which heat is absorbed from the surrounding is called endothermic reaction.
so
I think it's answer is 2nd option.
Energy, Temperature, and Changes of State
Matter either loses or absorbs energy when it changes from one state to another. For example, when matter changes from a liquid to a solid, it loses energy. The opposite happens when matter changes from a solid to a liquid.
Answer: 1.3% many crosslinks as isoprene units,
Explanation:
Given:
mass pf natural rubber= 200.0g
mass of sulphur = 4.8g
molar mass of sulphur =32g/mol
molar mass of isoprene = C5H8=( 12x5) +(1x8)= 68g/mol
Solution: we first find no of moles present in each using
no of moles = 
Isoprene: 200.0g x [1mole / 68g] = 2.94moles.
Sulfur: 4.8g x [1mole / 32g] x [1 mole crosslinks / 4 moles S] = 0.0375 moles crosslinks.
to find % crosslinked units, we have
0.0375 / 2.94 = 1.3% as many crosslinks as isoprene units,
13.48 is your answer.
M=moles/liters we have M=.115 and moles=1.55
Input those values into the equation
.115=1.55/L
Solve for L
1.55/.115=13.48
