Answer:
D
Explanation:
According to IUPAC nomenclature, a negative polyatomic ion has its name ending in 'ate' or 'ite'
As in carbonate (CO3^2-)
Arsenite (AsO3-)
Answer: option B. The number of the outer most energy level for elements in that period
Explanation:
This is a simple algebraic problem, specifically for the mixture type of problem. Let x be the mass of 40% solution and y be the mass of 70% solution. The first equation would then be:
x + y = 20 --> eqn 1
The second equation would be the mass balance shown below:
(x)(0.40) + y(0.70) = 20(0.52) --> eqn 2
Rearranging eqn 1,
x = 20 - y
Substitute this to eqn 2:
(20 - y)(0.40) + y(0.70) = 20(0.52)
Solve for y,
y = 8 grams
Finally, solve for x.
x = 20 - 8 = 12 grams
<em>Therefore, Serena needs 12 grams of the 40% solution and 8 grams of the 70% solution.</em>
Answer:
D. 6.25 J
Explanation:
∴ k = 50 N/m
∴ Δx = 0.5 m
⇒ EPE = 1/2*50 N/m*(0.5m)²
⇒ EPE = 6.25 N.m = 6.25 J
