<span>Hydroelectric energy uses the movement of water to spin a turbine and produce electricity. Coal is a fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways. Coal use is more common than the use of hydroelectric energy.</span>
Silicon has 14 protons Potassium has 19 electrons The neutrons are equal to the mass number minus the atomic number. Or the big number minus the small number on the periodic table. hydrogen 1 does not have a neutron.
iron =56 -26 for 30 neutrons in the nucleus
Chlorine 17 protons and 17 electrons. 18 or 19 neutrons on average.
Answer:
A machine have 75% efficiency means 25% of efficiency has been lost due to friction and a machine can work 75% only.
Answer:
option A is the correct answer .
Explanation:
as density = mass per unit volume
density = 7.5/2.5 = 3 gm / cm³ ..is the answer ...
pls mark my answer as brainlist plzzzz and plz vote
