Here is the answer for the three of them
<span>N20 = 16 e-
</span><span>SeCl2 =20
</span><span>PBr3 = 26
Remember that t</span><span>o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.</span>
Answer:
A
Explanation:
In chemistry, a mixture is a material made up of two or more different substances which are not chemically combined. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.
Sedimentary rocks have layers because of different depositions of sediments over time.
<h3><u>Answer;</u></h3>
pH = 4.20
<h3><u>Explanation;</u></h3>
pKa = -log(6.30 × 10^-5)
pKa = 4.20
Moles of Benzoic acid = volume × molarity
= 0.050L × 1.00M
= 0.050moles benzoic acid
Moles of the salt = 0.050L × 1.00M
= 0.050 moles salt
Therefore;
0.050mols / 0.1 L = 0.50M
0.050mols / 0.1 L = 0.50M
Thus;
pH = 4.20 + log(0.50/0.50)
pH = 4.20
