I think 3 of them are its been 1 half years since ive done this i dont take chemistry anymore
Where x represents the number of hours working as a babysitter and y represents the number of hours working as a cashier...
5x + 6y <u><</u> 90
x + y <u>></u> 20
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The 28 is the sum of the protons and neutrons in the element silicon.
ALL silicon atoms have 14 protons in the nucleus, so we can turn this into an equation:
#protons + #neutrons = 28
14 + #neutrons = 28
#neutrons = 14
#protons = 14
Bob adds heat to a liquid substance. When enough heat is added, the liquid would undergo a phase transition from the liquid to the vapor phase. This process is called evaporation. It is an endothermic process where heat should be supplied to the system for the process to happen. The temperature of the system, when enough heat is supplied to allow phase transition, is called the boiling point. It is the temperature when the substance starts to boil in turn to a gas or a vapor. The heat that is associated during boiling is called the latent heat of vaporization. It is the heat that is absorbed during the phase change without changing the temperature of the system.