Answer:
Explanation:
The two carbon atoms would be different. These different carbon isotopes are called isotopes. Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass number due to the difference in the number of neutrons in their various nuclei.
Carbon for example has 3 known isotopes which are:
¹²₆C ¹³₆C ¹⁴₆C
These isotopes have different places in nature where they can be found. Some can occur together naturally.
Isotopes have the same chemical properties because they share similar electronic configuration.
Answer : We can produce 125.7 g of
.
Explanation : The reaction will be

The molecular mass of
is 64.1 g/mol
and molecular mass of
is 34.1 g/mol
For every mole of
we would need twice of
moles, so for every 3 moles of
we need 16 moles of 
Now, we can calculate number of moles
2.61 X (3/16) = 0.49 moles
Here, the molecular mass of
is 256.8 g
multiplying it with the number of 0.49 moles we get, 256.8 X 0.49 = 125.7 g of
.
Hence, 125.7 g of
will be produced.
Answer:
The concentration of helium in the water is 2.405×10^-4 M
Explanation:
Concentration = Henry's law constant × partial pressure of helium
Henry's law constant = 3.7×10^-4 M/atm
Partial pressure of helium = 0.65 atm
Concentration = 3.7×10^-4 × 0.65 = 2.405×10^-4 M
The answer is (2) Copper. Because copper is consist of atom. If it is decomposed, the atom will be changed. While chemical change is just the break down and form of chemical bonds between atoms.