The Precambrian time refers to the time 4.5 billion to 542 millions year ago. This period is characterized by having reduced atmosphere and included reduced compounds. Scientists believed that atmosphere at that time was devoid of free oxygen and CO2 was present in excess. Before the complex life evolved on the Earth, the Precambrian Earth's ocean contained dissolved carbon dioxide.
I believe the answer would be d
Option 1 is the correct answer
Answer:
atomic number is 4 and neutron is 12
The best answer is B - the fish die.
Acid rain flows through soils. If the soil part of a watershed, aluminum is released from the soil and into the streams and lakes located in that watershed.
This lowers the pH in the lake from between 6 and 8 (which is the normal pH in lakes and streams) to less than 5.
Both increase of aluminum and lower pH are directly toxic to fish and they kill off fish populations
