6.0 g of copper was heated from 20 degree c to 90 degree c . How much energy was used to heat cu?
1 answer:
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Answer: atoms of hydrogen are there in
35.0 grams of hydrogen gas.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.
To calculate the moles, we use the equation:
1 mole of hydrogen =
atoms
17.5 mole of hydrogen =
atoms
There are atoms of hydrogen are there in
35.0 grams of hydrogen gas.
Answer : 121.5 <span>μCi
Explanation : We have Ce-141 half life given as 32.5 days so if the activity is 3.8 </span><span>μci after 162.5 days of time elapsed we have to find the initial activity.
We can use this formula;
</span>
3.8 /
= 
((0.693 X 162.5 ) / 32.5) = 121.5
<span>
On solving we get, The initial activity as 121.5 </span>μci
Explanation : We have Ce-141 half life given as 32.5 days so if the activity is 3.8 </span><span>μci after 162.5 days of time elapsed we have to find the initial activity.
We can use this formula;
</span>
3.8 /
<span>
On solving we get, The initial activity as 121.5 </span>μci