Answer:
78.3 × 10²³ atoms of helium are present in 52 g.
Explanation:
Given data:
Mass of He = 52 g
Number of atoms = ?
Solution:
First of all we will calculate the number of moles of He
Number of moles = mass /molar mass
Number of moles = 52 g/ 4 g/mol
Number of moles = 13 mol
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,
1 mole = 6.022 × 10²³ atoms of helium
13 mol × 6.022 × 10²³ atoms of helium / 1 mole
78.3 × 10²³ atoms of helium
Answer: 873 kJ of energy will be required to break two moles of hydrogen gas.
Above chemical equation shows that two moles of hydrogen gas is reacting with one mole of oxygen gas to give two mole of water molecule.
Bond energy of H-H = 436kJ
According to reaction we have two moles hydrogen,so energy required to break the
H-H bond in two moles of hydrogen gas will be:
= 872kJ
872kJ of energy will be required to break H-H bond in two moles of hydrogen gas.
Answer:Climate is defined as the average state of everyday's weather condition over a period of 30 years.[1][2] It is measured by assessing the patterns of variation in temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods of time. Climate differs from weather, in that weather only describes the short-term conditions of these variables in a given region.
Explanation:
As bond number increases (double bonds rather than single, triple rather than double etc. ), bond length decreases and bond energy increases
Reason-Charges that are spaced apart are described by a dipole moment. There are two critical criteria that must be taken into account when assessing if a molecule has a dipole moment. It must first possess polar covalent bonds. The individual dipoles must not cancel out in the molecular structure, which is the second requirement. Because Br2 is not a polar molecule, it lacks a polar covalent bond.A bond number is a simple addition of two numbers that total the sum. Using number bonds, one can quickly determine the answer without performing any calculations. We can see from the example that when we see a number bond, we know the answer without having to calculate.
Learn more about bond number here:
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Answer:
1 year- 1 mole
time in general- amount of matter
1 second- 1 atom/ particle
