Answer: a) 
b) 
c) 
d) 
Explanation:
General representation of an element is given as:_Z^A\textrm{X}
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
It is characteristic of a particular element.
Atomic number = Number of electrons = Number of proton
a) Z 74, A 186:
b) Z 80, A 201:
c) Z 34, A 76:
d) Z 94, A 239.:
Answer:
The farther away the planet the slower the revolution around the earth. the closer the faster.
Explanation:
its like a tetherball pole when it wraps around it gets closer and spins faster and faster untill it stops. Brainliest?
The difference in the concentration of a substance between two areas is called the concentration gradient. When a region has a higher particle concentration than another, this is known as a concentration gradient. A concentration gradient will cause particles in passive transport to diffuse down it from higher concentration to lower concentration until they are evenly spaced.
The gradual separation of a region of high density from a region of low density in a solution in terms of the concentration of a dissolved material. Understanding how ions and particles flow randomly in a solution or gas depends on the concentration gradient.
To learn more about concentration, click here.
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In an electrically neuteral atom, number of protons = number of electrons = atomic number.
Mass number = neutrons + protons/electrons/atomic number
Therefore,
neutrons = mass number - <span>protons/electrons/atomic number
Neutrons = 33 - 15 = 18
The answer is thus B. But this is the solution and explanation along with it as proof.</span>
The correct answer is C: the alkaline earth metals!
