Answer:
9945.6 J
Explanation:
Amount of heat = Mass * Heat Capacity * Temperature Change
Heat capacity of Water = 4.2 J/gC
Amount of heat = 64 * 4.2 * (69 - 32)
Amount of heat = 64 * 4.2 * 37
Amount of heat = 9945.6 J
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:
first we add the same direction. 12N + 32 N=44N .
then we add the forces. 54 up + 44N down= 10N up
Answer:
In chemistry, a symbol is an abbreviation for a chemical element. Symbols for chemical elements normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
Earlier symbols for chemical elements stem from classical Latin and Greek vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, Pb is the symbol for lead (plumbum in Latin); Hg is the symbol for mercury (hydrargyrum in Greek); and He is the symbol for helium (a new Latin name) because helium was not known in ancient Roman times. Some symbols come from other sources, like W for tungsten (Wolfram in German) which was not known in Roman times.
Explanation: