Answer:
450. g of 0.173 % KCN solution contains 779 mg of KCN.
Explanation:
Mass of the solution = m
Mass of the KCN in solution = 779 mg
Mass by mass percentage of KCN solution = 0.173%



1 mg = 0.001 g
m = 450,289 mg × 0.001 g = 450.289 mg ≈ 450. g
450. g of 0.173 % KCN solution contains 779 mg of KCN.
Answer:
m = 1.5 gram
Explanation:
Given that,
Density of protein gelatin, d = 3 g/L
The volume of protein gelatin, V = 0.5 L
We need to find the mass of the protein gelatin. The density of an object is given by :
d = m/V
Where
m is mass

So, the required mass is 1.5 gram.
Atomic number shows the number of protons in an atom's nucleus. If the atomic number is 30, then it has 30 protons. The question says it is neutral, so it must have the same amount of protons and electrons.
A is the correct answer based on this.