1) Evaporization is phase change process in which the water changes from a liquid to a gas (water vapor). Solar radiation is the source of energy for evaporation.
2) Condensation is phase change process in which the water changes from a gas to a liquid, the vapor becomes a cloud.
3) Precipitation is falling of the condensed water vapor as rain, snow, fog drip.
The water cycle (hydrological cycle) is the continuous movement of water all around the Earth.
The given above pretty much states already that with the presence of the calcium carbonate which acts as the buffer will allow the solution to withstand changes in acidity. The greater the amount, the higher chances that it will be able to withstand the said changes. Therefore, if Lake X had greater ppm of CaCO3 then, it will be able to withstand greater amount of acid rain.
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>
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between atoms.
Answer :
Explanation :
The aluminium and fluorine react to give ionic compound aluminium fluoride.
Aluminium has 1 valence electrons in their shell and fluorine has 7 valence electrons in their shell.
For the complete octet, both aluminium and fluorine exchange valence electrons to form an ionic compound.
The aluminium donates its three valence electrons to three fluorine atoms and they form one 
and three 
ions.
Electron transfer image is shown below.
