All of the elements are made up of atoms. Every atom is made up of 3 subatomic particles known as the electrons, protons and neutrons. Electrons are negatively charged particles while the protons are the positively-charged particles. Lastly, neutrons do not have any charge.
To solve this problem we will apply the concepts related to the Force of gravity from Newtonian theory for which it is necessary to

Where,
G = Gravitational universal constant
M = Mass of Earth
m = mass of Object
x = Distance between center of mass of the objects.
From this equation we can observe that the Force is inversely proportional to the squared distance between the two objects. The greater the distance, the lower the force of gravity and vice versa.

If you want to increase the force of gravity, you need to reduce the distance of the two. Therefore the correct option is B. Talk to the distance between them.
Answer:
C. Have no change in electrical charge
Explanation:
If a element gains neutron it become an Isotope. The electrical charge do not change for this, only the atomic mass changes when an element gains neutrons.
The electrical charge is affected when there is a variation in the number of electrons or protons in the element.
Answer: Primary succession is one of two types of biological and ecological succession of plant life, occurring in an environment in which new substrate devoid of vegetation and other organisms usually lacking soil, such as a lava flow or area left from retreated glacier, is deposited.
It could prevent the key from sinking because the wood would float.
It floats because it weighs less than amount of water it would have to push out of the glass if it sank. Wood, cork, and ice are all less dense than water, and they float; rocks are more dense, so they sink. A key would also be more dense causing it to sink.
Hope this helps,
Davinia.