Answer: 2 lone pairs, square planar
Explanation:
Using the VSEPR ( Valence Shell Electron Pair Repulsion)Theory
To calculate the number of lone pairs electron can be done using the formula;
Number of electrons = ½ (V+N-C+A)
V mean valency of the central atom
N means number of monovalent bonding atoms
C means charge on cation
A means charges on anion
Therefore, to calculate the number of lone pair electron C=A=0;
Number of electrons = ½ (8+4) = 12/2 = 6
Number of bonding pair = 4
Number of lone pairs of electron = 6-4 = 2
The hybridrization of the compound is sp3d2 because the number of electrons around the central atom is 6.
The geometry of the compound is square planar and this is because of the repulsion between the bonding pair of electrons and lone pair of electrons which causes the lone pair of electrons to lie in a perpendicular plane in order to acquire stability.
Answer:
B. temperature decreases as altitude increases.
Explanation:
Just like in the lower reaches of the atmosphere, the troposphere, in the mesosphere, temperature decreases as altitude increases.
The mesosphere is the third layer of the atmosphere just above the stratosphere.
- It begins at the top of the stratosphere and ends at the mesopause where the thermosphere begins.
- The mesosphere is often referred to as the middle layer.
With increasing height, the temperature of the mesosphere decreases significantly. The top of the mesosphere is one of the coldest part of the earth atmosphere. This is as a result of increasing atmospheric cooling by carbon dioxide in this region of the atmosphere.
Answer:
Option A. Addition
Explanation:
Unsaturated compounds under goes addition reaction to produce saturated compounds..
In the equation given above i.e
H2C=CH2 + F–F —> FCH2CH2F
we can see that the double in H2C=CH2 disappear by the reaction of F–F to produce FCH2CH2F which has no double. This simply indicates that the F–F was added to H2C=CH2. Hence, the reaction is called addition reaction.
Answer:- Yes, strontum bromide and potassium sulfate gives a precipitate of strontium sulfate.
Explanations:- As per the solubility rules, all compounds of alkali metals are soluble.
Sulfate of most of the alkaline earth metals like Ca, Ba and Sr are insoluble.
A double displacement reaction takes place when strontium bromide and potassium sulfate are mixed and a precipitate of strontium sulfate is formed:

Note: (aq) stands for aqueous and (s) stands for solid and here it's precipitate.