Question

Is anyone on here? Can someone help me with easy ninth grade Physical Science Questions?

Answer 1

@charlotte123

Answer 2

14. A scientist could use DNA as a molecular clock to do which of the following?

a. to determine the age of a very old rock
b. to determine the amount of DNA in a person's body
c. to determine how long ago two species of animals shared an ancestor*
d. to determine how many offspring a chicken has during its lifetime

Answer 3

What do all group 2 elements have in common?

a. They all gain two electrons to form a stable outer energy level.*
b. They form covalent bonds with halogens.
c. They all react easily with the noble gases.
d. They tend to form ionic bonds by losing electrons.

Answer 4

what you think the answers would be ?

Answer 5

The ones with the "*" beside them.

Answer 6

Which statement correctly compares barium nitrate (Ba(NO3)2) and scandium nitrate (Sc(NO3)3)?

a. They contain the same number of NO3 groups.*
b. They contain the same number of oxygen atoms.
c. They contain the same total number of atoms.
d. They contain the same number of elements.

Answer 7

I think it's D, not to sure. Based on what I've learned from middle school and some what chemistry teaching's.