Answer:
Element
Explanation:
Two of the same element may have differing numbers of neutrons, however, when it comes to protons, two of the same element will always have the same number of protons. Two different elements may have the same neutrons, but never protons.
Answer: ATP is the energy currency molecule which is required for cellular processes.
Explanation:
When the cell require metabolic energy to perform a particular a task. From the ATP or adenosine triphosphate molecule one of three phosphate molecule gets displaced and liberates the resulting molecule becomes adenosine diphosphate or ADP. The phosphate molecule is used by the cell to perform different cellular and metabolic functions as a source of metabolic energy. The phosphate is released by the hydrolysis of the phosphoanhydride bond with the other phosphate group.
Answer: The isotope is represented as 
Explanation:
General representation of an element is given as:
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
Atomic number = Number of electrons = Number of protons = 7 (for nitrogen)
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 = 7+8 = 15
Thus the isotope is represented as 
Answer: 0.123 M
Explanation:
According to the neutralization law:

where,
= molarity of
solution = ?
= volume of
solution = 15.00 ml
= molarity of
solution = 0.100 M
= volume of
solution = 18.44 ml
= valency of
= 1
= valency of
= 1


Therefore, the concentration of the unknown HBr solution is 0.123 M