Study the timeline. A timeline. 4.5 billion years ago, Earth is formed. 4.3 billion years ago, Earliest water. 4.1 billion years ago, Single celled life. 3.5 billion years ago, Earliest oxygen and photosynthesis. 2.5 billion years ago, Complex single celled life. 1.5 billion years ago, Multi cellular life. 500 million years ago, Land life. 300 million years ago, Dinosaurs. 200 million years ago, Mammals. 130 million years ago, Flowers. 5 million years ago, Humans.
Based on the timeline, about how many years ago could the oldest mammalian organism have lived?

5 million years
200 million years
1.5 billion years
4.5 billion years

Which of the following is a compound? a.carbon b.oxygen c.hydrogen d.water

The tendency of water molecules to stick together is referred to as a) adhesion b) polarity c) cohesion d) transpiration e) evaporation

Gusing the milligrams of ascorbic acid you entered above, the ratio of total sample volume to aliquot volume, and the total milligrams of the vitamin c tablet that you dissolved, calculate the mass of ascorbic acid in the vitamin c tablet for each trial. do this by scaling up to find the amount (mg) of ascorbic acid in your 250 ml flask. enter your calculated mass of ascorbic acid in the vitamin c tablet, for each trial. be sure to enter your calculated mass in the corresponding order that you entered your milligrams of ascorbic acid. the milligrams of ascorbic acid you entered for entry #1 previously should correspond to the mass of ascorbic acid that you enter for entry #1 here.