This question is asking for an element with 5 valence electrons. Just go to the row it is in (excluding transition metals) and count over.
The answer would be c. P
Answer:
DNA consists of molecules called nucleotides. Each nucleotide comprises a group of phosphates, a group of sugars and a base of nitrogen. The four forms of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The sequence of these bases defines the DNA instructions or genetic code.
Answer: There are 0.006 moles of acid in the flask.
Explanation:
Given: 
= 21.35 mL, 
= 0.150 M
= 25.0 mL, 
= ?
Formula used to calculate molarity of 
is as follows.
Substitute the values into above formula as follows.
As molarity is the number of moles of a substance present in a liter of solution.
Total volume of solution = 
= 21.35 mL + 25.0 mL
= 46.36 mL (1 mL = 0.001 L)
= 0.04636 L
Therefore, moles of acid required are calculated as follows.
Thus, we can conclude that there are 0.006 moles of acid in the flask.
Volume of H2 produced = 57.6576 L
<h3>Further explanation</h3>
Given
23.17 g Be
Required
Volume of H2
Solution
Reaction
Be(s)+H2O(g)→BeO(s)+H2(g)
mol Be :
= 23.17 g : 9 g/mol
= 2.574
From the equation, mol H2 : mol Be = 1 : 1, so mol H2 = 2.574
Volume H2(assumed at STP, 1 mol=22.4 L) :
= 2.574 x 22.4 L
= 57.6576 L
