Answer: 3
Explanation:
All elements in group 3 have 3 levels of energy.
Na (sodium) has 3 valences the inner has 2 electrons, the middle has 8 electrons and the outer has 1 electron.
This will continue across the group 3 adding one more electron to the outer valence until Ar (argon).
Remember the Octet rule of 8..?
Answer:
the selected one is the correct one
Explanation:
enzymes are protein molecules which are made of amino acids
B. Earth rotates on a tilted axis
The seasons are created by the differences in proximity to the sun from the earth being tilted towards or away from the sun.
An ecosystem is defined as a community of living organisms as well as the nonliving components in the natural environment (such as the air and the water) that interact together through their nutrition cycle and the flow of their energies.
Ecological systems provide purification of air and water. They cycle nutrients and are considered as massive containers for recycling/