Atomic number (Z) of tungsten is 74
Mass number (A) of tungsten is 184
Now:
Atomic number of an element = Number of protons = Number of electrons
Mass number = Number of Protons + Number of neutrons
In the case of tungsten
Total Number of electrons = 74
Jeffrey has already added 21 electrons
Number of electrons needed = 74 - 21 = 53
Ans (D) 53 more electrons are needed to complete the neutral atom of tungsten.
Answer:
A = 2A + 3B → 5C
Explanation:
The two molecule of A and three molecules of B will react to form the five molecules of C.
2A + 3B → 5C
Other options are incorrect because,
B = A₂ + B₃ → C₅
in this reaction one molecule of A₂ and one molecule of B₃ combine to form one molecule of C₅.
C = 2A + 5B → 3C
in this reaction two molecules of A and five molecules of B combine to form three molecule of C.
D = A₂ + B₃ → C₃
in this reaction one molecule of A₂ and one molecule of B₃ combine to from one molecule of C₃.
1 molecule CO2 has 2 atoms O.
1 mole CO2 has 2 moles O,
1.5 mole CO2 has 2*1.5 mole O=3.0 mole O