Answer:
5 neutrons
Explanation:
Both protons and neutrons have a mass of about 1 atomic mass unit (amu). The number in the notation for an isotope is its mass in amu. That means the number is essentially the sum of protons and neutrons in the isotope (electrons don't contribute significantly to the mass).
If lithium has 3 protons, lithium-8 has 8 - 3 = 5 neutrons.
If a theory is studied in let's say the 17th century, the theory has had many years to be studied and explained by many different people many different ways.
Substance is some matter (it can be solid liquid or gas) that has its own properties.. everything in this world are substances...
like for example: the bread that we consume has - wheat ..yeast.. sugar.. salt or some other substances
Since the bulb consumes 100 watts of power and its efficiency is 95%,
it generates 95 watts of light energy and 5 watts of heat energy whenever
it's turned on.
5 watts means 5 joules of energy per second.
(2.5 hours) x (3,600 seconds/hour) = 9,000 seconds
(9,000 seconds) x (5 joules/second) = 45,000 joules of heat in 2.5 hours