The moles are used to determine the atoms and molecules in a substance. It is used by chemists to determine the amount of reactants needed and products produced. Thus, option B is correct.
<h3>What are moles?</h3>
A mole is said to be defined as the estimation of the small entities like the atoms as that of the Avagadro's number 6.022 × 10²³. It defines the number of particles contained in a substance.
The moles of the substances are determined by the mass of the substance and its molar mass. The moles are given as,
Moles = mass ÷ molar mass
The moles give the estimation of the amount of the reactants needed to produce the products in a chemical reaction.
Therefore, option B. the moles tell the amount of the reactants required to produce the product.
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1. Radio isotopes are used in all the industries mentioned above, that is, nuclear power plants, pharmacology and agricultural studies. So the correct option is D.
2. The statement is true. Radio isotope is used in medicine mostly as a diagnostic tool to diagnose illnesses.
3. Nuclear wastes are enclosed in lead and buried in cement casks deep underground so that the lead, cement and the earth cover will act as radiation shield. The correct option is B.
4.This statement is false. The US has 75 different radioactive storage locations across USA.
5. This statement is false. Radioactive contamination can enter the body through inhalation, ingestion, absorption and through contact with skin or clothing materials.
6. The statement is false. Uranium fuel is not burned, it undergoes fission process.
7. This statement is true. This is because nuclear power production has less green house effects compare to fossils fuels.
8. This statement is false. Nuclear energy is not renewable and it pollutes the environment.
9. Nuclear power plants are favoured because the power produce by them are more reliable source of energy which does not deplete the ozone layer.
Answer:
The column of ethanol will be higher than the column of mercury.
Explanation:
The pressure (P) of a column of liquid can be calculated using the following expression.
P = ρ . g . h
where,
ρ: density of the liquid
g: gravity
h: height of the column
h = P / ρ . g
We can see that the height of the column is inversely proportional to the density of the liquid. The density of ethanol (0.789 g/mL) is lower than the density of mercury (13.6 g/mL). Then, under the same conditions, the column of ethanol will be higher than the column of mercury.
Answer: False.
The final pressure in the system is 4.14 atm
Explanation: Please see the attachments below
<u>Answer:</u> The electronic configuration of gallium is written below and number of valence electrons is 3.
<u>Explanation:</u>
Electronic configuration is defined as the representation of electrons around the nucleus of an atom.
Number of electrons in an atom is determined by the atomic number of that atom.
Valence electrons are defined as the electrons present in the outermost shell of an atom.
We are given:
An element Gallium having atomic number as 31.
Number of electrons = 31
Electronic configuration of Gallium is: 
This element has 3 electrons in its outermost shell. So, the number of valence electrons is 3
Hence, the electronic configuration of gallium is written below and number of valence electrons is 3.
