I thought the answer is d
Answer: C
Explanation:
In endothermic reactions, enthalpy is positive, and in exothermic reactions, enthalpy is negative, So, if enthalpy is positive, then it is an endothermic reaction, and hence is required for the reaction to occur.
The cubes have only the same volume, so the answer is c.
a) Group 2 elements have 2 electrons on their outer shell, so they form a 2+ charge.
b) they lose 2 electrons as they are transferred to the non metal.
c)They obtain this charge as when they are made into an ionic compound the 2 electrons on the outer shell are transferred to the non metal, meaning there are 2 more protons that electrons, giving it a positive charge.
hope this helps! :)
Answer:
In the given case, the atomic number of the given atom is 15, hence its nucleus contains 15 protons. The number of protons and electrons are the same in atom and that is what keeps it neutral. In the second case, the atomic number is 20. Hence, the atom will contain a total of 20 protons in its nucleus.
Explanation:
