Shoemaker-Levy-9 was a huge chunk of ice and dust that orbited the sun in a long, flat orbit before
Jupiter's gravity attracted it. Its was classified as a

i think it is true since you can test the answer and can use observations to complete it.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.

you did not give any options thus this is the best answer i can give to you with this little information you have given

> they are both natural and not man made

> they can be tracked and predicted by the right tools

-love shrooms