Answer:
gold
Explanation:
to work out density you do mass which is 38.6 divided by volume which is 2cm cubed and you get the answer of 19.3 so it is gold.
Because it represents 2 atoms of carbon not 2 molecules of carbon
Answer:
False
Explanation:
Half life is the time period at which the concentration of the radioactive substance in decay reduced to half.
<u>Thus, if the hydrogen-3 has gone 2 half lives, it means that it has first reduced to its half and then again the half of what it was, i.e. 1/4</u>
Thus, after two successive half-lives, the concentration must be 1/4 of the initial concentration and hence, the statement is false.
Answer:
6.67 moles
Explanation:
Given that:-
Moles of hydrogen gas produced = 10.0 moles
According the reaction shown below:-
3 moles of hydrogen gas are produced when 2 moles of aluminium undergoes reaction.
Also,
1 mole of hydrogen gas are produced when 
moles of aluminium undergoes reaction.
So,
10.0 moles of hydrogen gas are produced when 
moles of aluminium undergoes reaction.
<u>Moles of Al needed = moles = 6.67 moles</u>
Answer:
0.17 lb
Explanation:
78 g * (1 lb/454 g)=0.17 lb
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