First find the oxidation states of the various atoms:
<span>in Cr2O2 2- Cr @ +1; In NH3 N @ +3; in CrO3 Cr @ +3, N2 N @ 0 </span>
<span>Note that N gained electrons, ie, was reduced; Cr was oxidized </span>
<span>Now there is a problem, because B has NH4+ which the problem did not, and is not balanced, showing e- in/out </span>
<span>B.NH4+ → N2 </span>
<span>Which of the following is an oxidation half-reaction? </span>
<span>A.Sn 2+ →Sn 4+ + 2e- </span>
<span>Sn lost electrons so it got oxidized</span>
Answer: C. no new substances
are formed<span>
</span><span>
<span>In the
physical change of matter, there is no new substance that is formed. It is only
the appearance of the matter that is being changed and not its chemical
composition. Cutting, tearing and grinding are only some of the examples that
exhibit physical change. </span></span>
The volume of 1.00 lb of mercury metal : 33.352 ml
<h3>Further explanation </h3>
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:

ρ = density
m = mass
v = volume
Density of metal(mercury) = 13.6 g/ml
mass of mercury : 1 lb = 453,592 g
So the volume :

Answer:
D
Explanation:
My favorite pancake recipe
2 cups all purpose | plain flour, (290 g | 10 oz)
1/4 cup granulated sugar or sweetener, (60g | 2 oz)
4 teaspoons baking powder
1/4 teaspoon baking soda
1/2 teaspoon salt
1 3/4 cups milk, (440ml)
1/4 cup butter, (60g | 2 oz)
2 teaspoons pure vanilla extract
1 large egg
Combine everything in a bowl (separate wet and dry) and cook at medium low heat until it is brown and there are bubbles on top. Then serve with syrup. Good luck!!!
Those are types of water on a pH scale 7.0 and above are alkili water and anything under that is acidic