What is the main difference between an isotope and an ion?
a. an ion has extra protons.
b. an isotope has extra neutrons.
c. isotopes are radioactive while ions are not.
d. an ion always has a positive or a negative charge?

This line graph compares the growth of plants that were kept in the sun for different amounts of time.a)  on day 7, the plants kept in the sun for 3 hours were how tall? b)  on day 7, the plants kept in the sun for 6 hours were how tall? c)    on day 10, the plants kept in the sun for 9 hours were how tall? d)  on day 11, the plant that was grown with 1 hour of sunlight was how tall? e)  based on the graph, the plant grows best in what amount of sunlight?

Modern weaponry has increased the number of deaths in wars and violent conflicts.

Which diagram shows the correct way to represent an ionic compound of magnesium oxide?