According to the law of conservation of matter, the number of Atoms<span> is not changed by a chemical reaction.
</span><span>
They're the same before and after a chemical reaction</span>
Answer: Endothermic reaction.
Explanation: A chemical reaction in which energy is absorbed from the surrounding environment.
Answer: e. 4.8 h
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for rate constant
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) for 160.0 g to decay to 2.07 g
The time required for a 160.0-g sample of 158Eu to decay to 2.07 g is 4.8 hours
Answer:
1.67×10^25 molecules
Explanation:
No of molecules = no of moles × Avogadros number
No of moles= mass in gram / molar mass
No of moles of water in given sample = 500.3/18
= 27.79 moles
No of molecules = 27.79× 6.02×10^ 23
= 167.32×10^23 or 1.67×10^25