<u>Answer:</u> The correct answer is Option A.
<u>Explanation:</u>
Electronegativity is defined as the tendency of an atom to attract the shared pair of electrons towards itself whenever a bond is formed.
This property increases as we move from left to right across a period because the number of charge on the nucleus gets increased and electrons are attracted more towards the nucleus.
This property decreases as we move from top to bottom in a group because the electrons get add up in the new shells which make them further away from the nucleus.
Thus, the correct answer is Option A.
The correct option is B.
Stars live out most of their lives at MAIN SEQUENCE. Stars generally are divided into three major stages, these are:
1. Pro stars and pre-main sequence star
2. Main sequence and giant star
3. Variable stars
Major stages in the life of a star can last for millions of years.
Answer:
55.3 × 10²³ molecules
Explanation:
Given data:
Number of moles of C₁₁H₁₂O₂₂ = 9.18 mol
Number of molecules = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
For given data:
9.18 mol × 6.022 × 10²³ molecules /1 mol
55.3 × 10²³ molecules
C and D
surface water is evaporated by the sun and concentrated the ocean salt and oceans are diluted when rivers flow into them
Answer:
74.4 ml
Explanation:
C₆H₈O₇(aq) + 3NaHCO₃(s) => Na₃C₆H₅O₃(aq + 3CO₂(g) + 3H₂O(l)
Given 15g = 15g/84g/mol = 0.1786mole Sodium Bicarbonate
From equation stoichiometry 3moles NaHCO₃ is needed for each mole citric acid or, moles of citric acid needed is 1/3 of moles sodium bicarbonate used.
Therefore, for complete reaction of 0.1786 mole NaHCO₃ one would need 1/3 of 0.1786 mole citric acid or 0.0595 mole H-citrate.
The question is now what volume of 0.8M H-citrate solution would contain 0.0595mole of the H-citrate? This can be determined from the equation defining molarity. That is => Molarity = moles solute / Liters of solution
=> Volume (Liters) = moles citric acid / Molarity of citric acid solution
=> Volume needed in liters = 0.0.0595 mole/0.80M = 0.0744 Liters or 74.4 ml
