Answer:
(a) Barium is produced at the negative electrode
(b) Iodine is produced at the positive electrode
Explanation:
When an electric current is passed through a solution containing electrolyte, a non spontaneous reaction is stimulated. This results in the flow of <u>positively charged ions to negatively charged electrodes(</u><u>cathode</u><u>) and negatively charged ions to positively charged electrodes(</u><u>anode</u><u>)</u>
When an electric current is passed through molten 
in the electrolytic cell, the following reactions takes place:
→ 
+ 2
At the anode;
Iodine ions will lose an electron and will be oxidized to iodine
→ 
+ 
At the cathode;
Barium ions gains electrons and its reduced to barium metal
+ 
→ Ba
Answer: Convection Currents
Explanation: The mantle rock is solid and denser because it is cooler. This means it will sink closer to lower mantle as warmer, lense dense rock/magma moves upwards.
Answer:
1. 8.7moles of H2
2. 2.25moles of O2
Explanation:
1. 2NH3 —> N2 + 3H2
From the equation,
2moles of NH3 produce 3 moles of H2.
Therefore, 5.8moles of NH3 will produce Xmol of H2 i.e
Xmol of H2 = (5.8x3)/2 = 8.7moles
2. C3H8 + 5O2 —> 3CO2 + 4H2O
From the equation,
5moles of O2 produced 4moles of H2O.
Therefore, Xmol of O2 will produce 1.8mol of H2O i.e
Xmol of O2 = (5x1.8)/4 = 2.25moles
The ability to attract an electron for bonding is called (option B) Electronegativity.
Answer: 1. C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur
2. B) 
3. B) Fluorine
Explanation:
1. A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Electronegativity difference = electronegativity of sulphur- electronegativity of silicon = 2.5 -1.8 = 0.7
Thus as electronegativity difference is less than 1.7 , the cond is polar covalent and as electronegativity of sulphur is more , the electrons will be more towards sulphur.
2. A molecular compound is usually composed of two or more nonmetal elements. Example:
Ionic compound is formed by the transfer of electrons from metals to non metals. Example: 
, 
and 
3. 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 K is having an oxidation state of +1 and as the compound formed is KZ, the oxidation state of non metallic element Z should be -1. Thus the element Z is flourine which exists as diatomic gas 
