Valence electrons are the electron on the outer energy level and they are important because they tell if that element is compatable
Polar because it always is below 32 degrees and has no rainfall
Answer:
Carbon dioxide is a greenhouse gas and traps heat in the atmosphere. Without it and other greenhouse gases, Earth would be a frozen world. But humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago, and Earth is becoming a warmer place.
The answer is A. Transport of water and minerals to the shoot system
