For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
What are you trying to ask
Answer:
3 electrons
Explanation:
aluminum : [Ne]3s23p1 [ N e ] 3 s 2 3 p 1 . It loses 3 electrons from 3s and 3p orbitals and attains the noble gas configuration of Neon.
Your question looks a bit incomplete as you have the same contents in options a) and d). According to your list, I can't see the correct answer, but I can give you one.The difference between the potential energy of the products of the potential energy of the reactants is equal to the enthalpy of the reaction.
