Answer: A) polar molecule
Explanation: Polar molecules are molecules which contain atoms of different electronegativities.
Non polar molecules are molecules which contains atoms of same electronegativities.
Water is a polar covalent molecule formed by unequal sharing of electrons. Oxygen being more electronegative tend to keep the electron pair towards itself thus generating a partial negative charge. The hydrogen acquire a partial positive charge thus resulting in a polar molecule.
The bent shape is due to repulsion between lone pairs and bond pairs of electrons.
Answer:
The limiting reacting is O2
Explanation:
Step 1: data given
Number of moles O2 = 21 moles
Number of moles C6H6O = 4.0 moles
Step 2: The balanced equation
C6H6O + 7O2 → 6CO2 + 3H2O
Step 3: Calculate the limiting reactant
For 1 mol C6H6O we need 7 moles O2 to produce 6 moles CO2 and 3 moles H2O
O2 is the limiting reactant. It will completely be consumed (21 moles).
C6H6O is in excess.
For 7 moles O2 we need 1 mol C6H6O
For 21 moles O2 we'll need 21/7 = 3 moles C6H6O
There will remain 4.0 - 3.0 = 1 mol C6H6O
Step 4: calculate products
For 1 mol C6H6O we need 7 moles O2 to produce 6 moles CO2 and 3 moles H2O
For 21 moles O2 we'll have 6/7 * 21 = 18 moles CO2
For 21 moles O2 we'll have 3/7 * 21 = 9 moles H2O
The limiting reacting is O2
<u>Answer:</u> The fraction of atom's mass contributed by nucleus is 0.99
<u>Explanation:</u>
Nucleons are defined as the sub-atomic particles which are present in the nucleus of an atom. Nucleons are protons and neutrons.
The isotopic symbol of Helium-4 atom is 
Number of electrons = 2
Number of protons = 2
Number of neutrons = 4 - 2 = 2
We are given:
Mass of He-4 atom = 
Mass of 1 electron = 
Calculating the mass contributed by the nucleus = 
Mass of the nucleus of He-4 atom = 
To calculate the fraction of atom's mass contributed by the nucleus, we use the equation:

Putting values in above equation, we get:

Hence, the fraction of atom's mass contributed by nucleus is 0.99
Answer:
The difference is 293.15 Kelvin.
Explanation:
Given data:
Temperature difference of matter = 20°C
Temperature difference of matter in kelvin = ?
Solution;
Formula:
0°C +273.15
now we will put the values instead of 0.
20°C + 273.15 = 293.15 K
Thus, the temperature difference between two sample is 293.15 K.