How long has there been life on Earth?

4.6 billion years

3.7 billion years

65 million years

3 million years

The abundance of 12c is 98.9%. 13c is another naturally occurring isotope. what is the percent abundance of 13c?

The molarity (M) of a solution is equal to the: A) number of grams of solute/liter of solvent B) number of grams of solute/liter of a solution C) number of moles of solute/liter of solvent D) number of moles of solute/liter of solution

What is the diffrence between hight consentration and low concentration

1. Directions: Select each correct answer. Biotic factors of an ecosystem could include which of the following? A. all types of plants B. the quantity of water available C. the temperature range D. all animal populations

Why are nonnative species a threat to biodiversity? Why are nonnative species a threat to biodiversity? A. They often use up resources that other organisms need. B. They are not able to successfully breed in the wild. C.

What does the dashes line represent? A. Medium B. Boundary C. Normal D. Incident Ray

Only a small amount of cerium oxide nanoparticles is needed because the nanoparticles ... 1) are elements 2) are very reactive 3) have a high surface area to volume ration

Describe the solubility of water compared to ethanol?

When the free-energy change (AG) of a reaction is negative, the reaction is said to be: Endergonic Non spontaneous Spontaneous Endothermic

The solubility of carbon dioxide gas in water can be increased by