Answer:
The element belongs to group 15 of the present periodic table
Explanation:
Isotopes have the same proton number, what differs is that they have different number of neutrons.
Now since the half-sum of their neutrons is 19, the total number of neutrons would be 19 * 2 = 38 neutrons.
Also, their masses add up to be 68, since the total mass equals sum of neutrons and sum of protons, this means that the total number of protons is 68-38 = 30
Since this is equal in both isotopes, this means that the proton number of the element is 30/2 = 15
The atomic number is the number of protons in the nucleus of an atom. Since the atomic number is 15, this element is phosphorus and it belongs to group 15 of the present periodic table
Answer:
c. D represents ion-dipole forces, which are stronger than the force represented by C.
Explanation:
From the map:
D represents ion-dipole forces.
C represents H-bonding forces.
Ion dipole forces are the forces between a charged ion and polar molecule and it is electrostatic in nature.
Hydrogen bonding is a special case of dipole-dipole forces and it is present when there is a H=atom bonded to an electronegative atom such as: N, O, and F.
Ion dipole forces is stronger than that of H-bonding.
so, the right choice is:
c. D represents ion-dipole forces, which are stronger than the force represented by C.
The answer should be: <span>D. The reaction rate is equal in both directions
In the equilibrium state, the rate of reaction to the right is same as the reaction to the left. Because of this, the concentration of the reactant and product will be kept same.
It might seem like the reaction is stopped because there is no change in the concentration, but it wasn't. Adding a reactant or product will break the equilibrium state.</span>
The answer is:
B.electromagnetic energy to chemical energy
Electromagnetic u.v rays from the sun act on chemical substances in the plant chloroplasts producing chemical energy stored and used by the plant.