An atom Y has atomic number 15. It accept three electrons in order to become stable. Determine the I. Number of protons ii. Number of electrons after accepting electrons iii. Charge on the atom before accepting electrons iv. Charge on the atom after accepting electrons.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )

When measuring volume, why is it important to use the correct tools and units to attain the greatest accuracy? use specific examples from the lab to support your answer. (5 points)