Unit 8 Lesson 1 Quiz 1.
0:16
A tennis ball falls off a shelf and bounces several times. Each bounce is lower than the
one before. Soon the ball stops. Why doesn't the ball keep bouncing?
A. O The energy becomes stored in the ball.
B. Some of the energy is changed into mass.
C. O Energy is transferred to the air and ground.
D. The air and ground slowly destroy the ball's energy.

c took test

Explanation:

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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.

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr