Sodium/Atomic number
11
Gold/Atomic number
79
Potassium/Atomic number
19
Silicon/Atomic number
14
Answer:
0.028kg
Explanation:
We were given 2.6 × 1023 molecules of SO 2 That means that
N = 2.6 × 1023 molecules
Use
n (number of moles) = N
NA (Avogadro's constant)
to get
n =2.6×1023 molecules
6.02 ×1023 molecules/mol = 0.432 moles
Now use
m = n × M (molar mass)
to get
m = 0.432 mol × 64.066 g/mol = 27.677 g
So
m (in kilograms) = 27.677 g
103 g/kg = 0.028 kg
You are looking for an element in the fourth period and a transition metal. As most have about 3 valence electrons. Gallium and Scandium work perfectly.
Answer:
B. 0.5 molar
Explanation:
Given data:
Initial concentration = 0.40 M
Initial volume = 750 mL
Final volume =750 - 150 mL = 600 mL
Final concentration = ?
Solution:
Molarity is the number of moles of solutes in litter of solvent. In given problem it is stated that when the solution is uncovered solvent evaporate it means molarity is changed. we can calculate the new molarity with the following formula.
C₁V₁ = C₂V₂
C₁ = initial concentration
V₁ = initial volume
C₂ = final concentration
V₂ = final volume
Now we will put the values in formula.
C₁V₁ = C₂V₂
0.40 M × 750 mL = C₂ × 600 mL
300 M.mL / 600 mL = C₂
0.5 M = C₂
<span>Nitrogen-14 should be the correct response.</span>
