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 
Answer:
Some common compounds in our daily lives:
Water, H2O. We need this for survival, because it serves a lot of functions in our body, such as being a medium for chemical reactions in our cells.
Carbon Dioxide, CO2. It is one of the components of air, our body also produces CO2 during respiration.
Sodium chloride, NaCl. Table salt is mostly made of sodium chloride. It is also found dissolved in sea water.
Methane, C2H4. This is a common fuel for generating electricity. It can also be found (small amounts) in air.
Nitrogen Dioxide, NO2. It can also be found in air, and it is one of the common air pollutants brought by burning of fossil fuels.
Answer:
7.12 × 10⁻³ M/s
Explanation:
Step 1: Write the balanced reaction
2 SO₂ + O₂ ⇒ 2 SO₃
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of O₂ to SO₃ is 1:2.
Step 3: Calculate the rate of formation of SO₃
The rate of loss of O₂ is 3.56 × 10⁻³ mol O₂/L.s. The rate of formation of SO₃ is:
3.56 × 10⁻³ mol O₂/L.s. × 2 mol SO₃/1 mol O₂ = 7.12 × 10⁻³ mol SO₃/L.s
1)sodium chloride/common salt
2)sodium hydroxide
3)sodium carbonate/washing soda
4)sodium bi-carbonate/baking soda
5)calcium hypochlorite/bleaching power
6)hemihydrate calcium sulphate/plaster of Paris
7)calcium sulfate
8)copper sulfate
9)bororn trifluoride
10)potassium nitrate
I could only find ten examples
Answer: The law of conservation of mass is reffering to the fact that energy cannot be created or destroyed. So when you speak about atoms not being created or destroyed it is the same thing. Unless you're talking about an atomic bomb where the atoms are split.
