This is being graded.

Great answers only

Explanation:

When a ball is at its highest point, its acceleration is 0. The only thing pulling it down, is gravity so, the correct option is D. Downwards.

I'm not sure however due to the fact that the arrows on the other options are facing backwards meaning the ball would go backwards; and for the one option the ball is going up. However, the ball isn't going backwards nor up, so it must be D. If I am wrong I greatly apologize.

i would think it's food chain

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.