The atoms of elements can gain or lose electrons and become ions. Ions are charged particles that have gained or lost electrons. The atoms of elements can gain or lose electrons to form monatomic ions (made from a single atom of an element).
The molar mass of CO2 can be calculated as follows;
CO2 — 12 + (16x2) = 12+ 32 = 44 g
Therefore molar mass of CO2 is 44 g/mol
In 44 g of CO2 there’s 1 mol of CO2
Then 1 g of CO2 there’s 1/44 mol of CO2
Therefore in 78.3 g of CO2 there’s — 1/44 x 78.3 =1.78 mol of CO2
The answer is B
Vaporization
Number of moles = mass of Ni /molecular mass of Ni
mass of nickel = 86.4 g
molecular mass of nickel = 58.69
number of moles of Ni in 86.4 g
=86.4/58.69
=1.472 mol
(rounded to four significant figures instead of three because the first digit of the answer starts with a 1).
Answer:
C. naturally uncombined with other elements.
Explanation: Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air.
