ROW - ( 3 ) is correct
<u>SYSTEM</u><u> </u><u>(</u><u>A)</u>
Respiratory system - here gaseous exchange takes place.
<u>SYSTEM</u><u> </u><u>(</u><u>B)</u>
Digestive system - here nutrients from food is absorbed and assimilated .
<u>SYSTEM</u><u> </u><u>(</u><u>C)</u><u> </u>
Excretory system - removal of waste occurs
Answer:
The 2s orbital is at a higher energy level.
Explanation:
1s and 2s are the sub-orbitals that are located in an atom. They are nearest to the nucleus and are found on the s sub-orbital. The difference between 1s and 2s is the difference in their level of energy. 1s has low energy as compared to 2s. 1s orbital has the lowest energy because it is located closed to the nucleus. 2s orbital has higher energy than 1s because it's orbit is larger than 1s.
Organisms within each group are then further divided into smaller groups. These smaller groups are based on more detailed similarities within each larger group. This grouping system makes it easier for scientists to study certain groups of organisms.
<span>The addition and subtraction of negatively charged electrons can easily change an atom’s charge, because they perpetually spin in valence shells outside the nucleus. It is easier for a neighboring atom to share or steal an electron rather than a positively charged proton, which is found in the nucleus. It requires a strong energy input to split a proton free from other protons and neutrons. thus, the atoms lose or gain electrons from neighboring ones and become what is known as "ions". Hope it helped!</span>