Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here manganese is having an oxidation state of +4 called as cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give 
which written in simplest whole number ratios to give neutral 
Answer:
The reasons why the seemingly floating bubbles disappear was that they tend to loss their latent heat to the water molecules at the surface water.
Explanation:
Heat energy has a considerable effect on the velocity of molecules including water. The water molecules below the container will receive much more heat energy than those above it. This heat energy in the form of specific heat capacity and latent heat that result in the increase in the speed of individual molecules of water and finally to the escape of the molecules to a colder region of the container, in this case the upper region. At the collision of the bottom water to the surface water, they tend to exchange their heat content, the hotter molecules will lose their heat to the cold ones. When the formerly hot molecules encounter this, it will result in lowering the temperature and consequentially to the reduction of their movement, once in the form of bubble, now become ordinary water. This convectional transfer of heat energy will continue until the whole system has a uniform temperature depending on the consistency of the heat source.
Explanation:
I think the answer is this for a better check mass- mass ratio in stoichiometry lesson
Answer:
B
Explanation:
Heating a piece of iron until it glows.
