4) A cation is an atom that has a. Gained one or more electrcns
b. Gained a negative charge
c. Obtained a positive charge
d. The ability to repel electrons

h let me think

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year

a electronegativity decreases beacuse the size of nucleus is bigger.