Cl2(s); oxidation number 1 is the incorrect choices in oxidation number.
Explanation:
In the elemental form oxidation state is zero. Here chlorine is present in elemental form so oxidation state is zero.
Oxidation number depends on the number of electrons gained or lost by an atom of the element say in compound formation.
If electron is gained oxidation number becomes negative.
If electron is lost then oxidation number is positive.
If the octet rule is fulfilled that valence shell is filled them atomic number gets zero. Since Cl2 is in neutral state the oxidation number is 0.
Oxidation number in general can be made out by checking the valency of the element as oxidation number is also equal to the valency.
The material, Brass is not an element. The different elements can be seen on the periodic table. Anyway, brass is an alloy of metal. Although, gold, silver, copper and many others are elements. Hope i helped. Have a nice day.
Answer:
as no. of protons is equals to the no. of electrons so, it is a neutral atom.
but, as Atomic No. = Mass No. - No. of neutrons
Atomic No. = No. of protons = 18
so, Mass No. = Atomic No. + No. of Neutrons= 18 + 20 = 38
so, correct option is C.
Explanation:
We see that in 1 rock, there are 31 atoms of Argon and 1
atom of Potassium so the relative concentration of Potassium is:
1 / 32
or can be written as:
1 / 2^5
So this means that 5 half-lives have passed.
So the years are:
<span>years passed = 5 * 1.25 billion years = 6.25 billion years</span>
