Answer:
H2Br + 2KOH ----- K2Br + 2H2O
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds. Elements: are pure substances made up of only l type of atom. Atoms of the same element are identical in properties.
C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
Answer:
<span>ρ≅13.0⋅g⋅m<span>L<span>−1</span></span></span> = <span>13.0⋅g⋅c<span>m<span>−3</span></span></span>
Explanation:
<span>Density=<span>MassPer unit Volume</span></span> = <span><span>75.0⋅g</span><span><span>(36.5−31.4)</span>⋅mL</span></span> <span>=??g⋅m<span>L<span>−1</span></span></span>
Note that <span>1⋅mL</span> = <span>1⋅c<span>m<span>−3</span></span></span>; these are equivalent units of volume;
i.e. <span>1⋅c<span>m3</span></span> = <span>1×<span><span>(<span>10<span>−2</span></span>⋅m)</span>3</span>=1×<span>10<span>−6</span></span>⋅<span>m3</span>=<span>10<span>−3</span></span>⋅L=1⋅mL</span>.
INFORMATION:
We must find the number of valence electrons for magnesium
STEP BY STEP EXPLANATION:
In order to know the number of valence electrons for Mg, we need to locate the element in the periodic table
Since Mg is in the second group of the periodic table, it has two valence electrons.
ANSWER:
B) 2
