Answer:
element
Explanation:
an element is something made up of only one type of atom
From Q = mcΔΤ, the specific heat capacity, c, of the metal that was cooled is c = Q/mΔT = (-769 J)/(46.4 g)(30.0 °C - 101.0 °C) = 0.233 J/g °C. From the table, it appears that this is the specific heat capacity of silver. So, the metal is most like silver.
Note: The value for Q was written as a negative value in the equation as heat energy was given off by the metal when the metal was cooled (from the metal’s point of view, it’s losing heat energy).
Answer:
No. of atom =
no.of moles x avagardro's number xatomicity
= weight /molar mass x No x atomicity
=8.2/142 x6.02x10^23 x 4
=0.346 x 10^23(approximately)
Answer:
Carbon - 13
Explanation:
For most of the elements other than that of hydrogen, the isotopes are named for the mass number.
Example : Carbon atoms with 6 neutrons have mass number of 12 ( as
), so they are known as carbon-12.
Given that:
Protons = 6
Neutrons = 7
Mass = 6 + 7 = 13
So the name is Carbon - 13 . The symbol is 
Molar mass Li2CO3 = 73.89 g/mol
Molar mass Li = 6.94g/mol Li = 6.94*2 = 13.88g
% LI = 13.88/73.89*100 = 18.78% perfectly correct.