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:
power is work/time so 10,000j/5s=2000J/s
Answer:
- <em>The partial pressure of oxygen in the mixture is</em><u> 320.0 mm Hg</u>
Explanation:
<u>1) Take a base of 100 liters of mixture</u>:
- N: 60% × 100 liter = 60 liter
- O: 40 % × 100 liter = 40 liter.
<u>2) Volume fraction:</u>
At constant pressure and temperature, the volume of a gas is proportional to the number of molecules.
Then, the mole ratio is equal to the volume ratio. Callin n₁ and n₂, the number of moles of nitrogen and oxygen, respectively, and V₁, V₂ the volume of the respective gases you can set the proportion:
That means that the mole ratio is equal to the volume ratio, and the mole fraction is equal to the volume fraction.
Then, since the law of partial pressures of gases states that the partial pressure of each gas is equal to the mole fraction of the gas multiplied by the total pressure, you can draw the conclusion that the partial pressure of each gas is equal to the volume fraction of the gas in the mixture multiplied by the total pressure.
Then calculate the volume fractions:
- Volume fraction of a gas = volume of the gas / volume of the mixture
- N: 60 liter / 100 liter = 0.6 liter
- V: 40 liter / 100 liter = 0.4 liter
<u>3) Partial pressures:</u>
These are the final calculations and results:
- Partial pressure = volume fraction × total pressure
- Partial pressure of N = 0.6 × 800.0 mm Hg = 480.0 mm Hg
- Partial pressure of O = 0.4 × 800.0 mm Hg = 320.0 mm Hg
Solar: rays from the sun shine on solar pannels creating energy which is a renewable energy.
Water: water stored at a dam flows through turbines creating energy which is a renewable energy
Fossil fuels: fossil fuels are extracted from the ground the burned to create energy and this is a nonrenewable resource.
Hope this helps :)