B. 1 to 8
C. more than 8
D. It depends on what the element is.
Answer:
Number of neutrons = 7
The number of protons = The number of electrons = 5
Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.
This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.
Thus, atomic number = 5
Since, it is a neutral atom, The number of protons = The number of electrons = 5
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Mass number = Number of protons + Number of neutrons
12 = 5 + Number of neutrons
Number of neutrons = 7
(2) molecular structures
(3) ionization energies
(4) nuclear charges
Answer:
Due to molecular structures.
Explanation:
The different forms of phosphorus (white, black or red) are allotropes of phosphorus.
They differ in molecular structures.
White phosphorus: It has four phosphorus which form a tetrahedral shape.
Black phosphorus : It has orthorhombic structure and due to interlinked six membered rings, it is least reactive.
Red phosphorus: It is formed on heating white phosphorus. It is initially amorphus and turns crystalline on further heating.
Answer :
The parent and daughter concentrations (in percentages) is, 60 % and 40 % respectively.
The age of rock is
Explanation :
First we have to calculate the parent and daughter concentrations (in percentages).
and,
As we know that, the half-life of uranium-238 = years
Now we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = ?
a = initial amount of the reactant = 3 g
a - x = amount left after decay process = 1.8 g
Now put all the given values in above equation, we get
Therefore, the age of rock is