A. Which of these statements about a column of the periodic table is true?
The elements have similar characteristics.
b. The elements have a wide range of characteristics.
C. The elements have the same atomic number.
d. The elements have the same atomic mass.

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

How does litmus paper indicate an acid?

What is the relationship of air masses and the temperature of oceans?