D since Francium has an atomic number (mass) of 87
Firstly, carbon isn't a metal.
Boron is a metalloid.
Beryllium is the least metallic alkaline earth metal, and lithium is the least metallic alkaline metal.
Both are metallic, and have metallic appearances and conduct electricity, but beryllium is more brittle than lithium.
So, I'd say Li and Be are equal.
Answer:

Explanation:
Hello!
In this case, since isotopes of the same element have the same number of protons and electrons but different atomic mass, we can compute the number of neutrons by subtracting the number of protons to the atomic mass of the isotope; thus, for Ga-69 and Ga-71 (rounded up to whole numbers), we obtain:

Best regards!
Explanation:
Because molarity is classified as moles of solute per liter of water, dilution of the water may result in a reduction of its concentration.
Therefore, because the amount of moles of solute has to be constant for dilution, you will use the molarity and volume of that same target solution to calculate how many moles of solute will be present in the sample of the stock solution that you dilute.
c = 
⇒ n
=
c
⋅ V
= 0.250 M ⋅ 6.00 L =
1.5 moles HCl
Now all you have to do is figure out what volume of 6.0 M stock solution will contain 1.5 moles of hydrochloric acid
c = 
V = 
=
=
0.25 L
Expressed in milliliters, the answer will be
→ rounded to two sig figs