Answer:
half life = 25 days
Explanation:
Given data:
Total amount of sample = 40 mg
Sample left after 50 days = 10 mg
Half life of P³³ = ?
Solution:
<em>1st step:</em>
when time is zero = 40 mg
1 half life = 40/2 = 20 mg
2 half life = 20/ 2= 10 mg
<em>2nd step:</em>
<em>Elapsed time/ half life = HL</em>
half life = 50 days/ 2
half life = 25 days
Answer:

Explanation:
Hello!
In this case, when determining empirical formulas by knowing the by-mass percent, we first must assume the percentages as masses so we can compute the moles of each element:

Now, for the determination of the subscript of each element in the empirical formula, we divide the moles by the fewest moles (P or N):

Thus, the empirical formula is:

Regards!
a. 43.1 g
b. 38.2%
<h3>Further explanation</h3>
Given
32.5 grams of NaOH
Required
The theoretical yield of Na₂CO₃
The percent yield
Solution
Reaction
2NaOH(s) + CO₂(g) → Na₂CO₃(s) + H₂O(l)
mol NaOH :
= mass : MW
= 32.5 : 40 g/mol
= 0.8125
mol Na₂CO₃ from the equation :
= 1/2 x mol NaOH
= 1/2 x 0.8125
= 0.40625
a.
Mass Na₂CO₃ :
= mol x MW Na₂CO₃
= 0.40625 x 106 g/mol
= 43.0625≈43.1 g
b. % yield = (actual/theoretical) x 100%
%yield = 16.45/43.1 x 1005
%yield = 38.17%≈38.2%
1 wavelength, 2 crest, 3 trough, 4 wave height <3
Answer:
Tetrahedral
Explanation:
For the repulsion of the free electron pair theory, the shape of a molecule will be to repel the bonds and the free electrons on the central atom. In a molecule of carbon tetrachloride, the central atom (C) has no free electrons, so, the shape that repels better the charge is tetrahedral, as shown below.