Tell your teacher. They'll know what to do and it's best to report it to them.
Answer:
a. because it is an element
Explanation:
its pure because it only has one type of atom, making it an element
Answer: 4.15234 m
512 g H2O * 
= 0.512 kg H2O
Nitric Acid: HNO3 = 1.008 + 14.007 + 3(15.999) = 63.012 g/mol
H = 1.008 g/mol
N = 14.007 g/mol
O3 = 3*15.999
134 g HNO₃ * 
= 2.126 mol
m = 
= 4.15234 m
<h2>Answer:</h2>
B) endothermic reaction.
<h2>Explanation:</h2>
Melting of ice is endothermic because it is taking heat from the environment, feeling cold, because it requires energy to break the ice bonds. It's also why you feel cold when wet it takes energy to evaporate water. The ice absorbs the energy from the environment. Its internal potential energy increases, therefore, it's endothermic. It also increases the entropy of reaction.
