Answer: The new pressure is 3 psi.
Explanation:
Given:
= 12 psi, 
= ?, 
Formula used is as follows.

Thus, we can conclude that the new pressure is 3 psi.
Answer:
A group of dissimilar elements with a net charge remaining is called a polyatomic ion.
Explanation:
Answer: 173 g ( 0.17 kg in right accuracy)
Explanation: Amount in moles is n = N/Na = 2.0·10^24 / 6.022·10^23 (1/mol).
n = 3.32116 mol. M(Cr) = 52.00 g/mol and mass m = nM = 172.7 g
A) The class and C) Family would be the only accurate option. Here are the levels from largest to smallest: <span>kingdom, phylum, class, order, family, genus and species.</span>