<u>a) Answer: </u>
<em>Number of molecules in 1 mole</em>
<u>Explanation:</u>
a) Whether we take any of the substance among all three of the given substances they will have the same number of molecules in 1 mole of the substance is considered and the value for this will be 
<u>b) Answer: </u>
<em>In the given question </em><em>mass of the substance</em><em> which is </em><em>greatest</em><em> is asked for </em><em>one mole</em><em> and we also know that </em><em>mass of one mole is given by molar mass. </em>
<u>Explanation:</u>
b) It is known that
is the molar mass for oxygen which is greater than that of hydrogen while fluorine has a molar mass of
which on comparison shows that, it is the highest amongst all three.
Atoms with the same number of protons but different masses are called Isotopes.
<h3>What are Isotopes?</h3>
An isotope is one of two or more chemical elements that exist in different forms. Varied isotopes of an element have the same atomic number and protons in their nuclei, giving them the same atomic weight. However, each elemental isotope has a different amount of neutrons, which changes its atomic weight.
isobars - Isobars are atoms (nuclides) of several chemical elements that have diverse chemical characteristics but share the same physical characteristics. So, we may define isobars as elements with the same mass number but a different atomic number.
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Answer: the density of the rock
55.91g/ml
Explanation:
The density of the rock after it had being placed in the cylinder of water so the calculation should look like this:
Volume of water substract the mass of the rock:
And that is 142.5 ml - 86.59g =
Answer 55.91 g/ml
So the density of the rock is 55.91g/ml
The correct answer is Ozone.
Ozone, sometimes known as O3, is a poisonous and unstable gas. Ozone is a potent allotrope of oxygen; it absorbs heat when it is present in large quantities all over the earth. A molecule called ozone has three oxygen atoms in it. At ground level, it is dangerous and unstable. O3 O3's efficacy in treating infections, wounds, and several disorders has been extensively established. Before the turn of the century, it was employed to sterilize drinking water. One study found that ozone could cure 114 different ailments. Headaches, coughing, a dry throat, difficulty breathing, a heavy feeling in the chest, and fluid in the lungs can all be side effects of ozone exposure.
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