How long has there been life on earth?

a. 4.6 billion years,

b. 3.7 billion years,

c. 65 million years,

d. 3 million years

A student performs a dehydration experiment and starts with 6.79 grams of hydrate. After heating the hydrate and allowing it to cool, the student weighs the anhydrous salt. The mass of the resulting anhydrous salt is 3.17 grams.

An equilibrium mixture of SO 2, O 2, and SO 3 gases at 1500 K is determined to consist of 0.344 mol/L SO 2, 0.172 mol/L O 2, and 0.56 mol/L SO 3.

Calculate the mass % of magnesium sulfate (assume that there is a 1:1 mol ratio between sulfate and magnesium sulfate) in the original sample. Report your answer without units and use 3 sig figs, i. e. 55.23543% would be entered as 55.2

Using sugar as an alternative fuel source raises many concerns. which of the following is not a concern? A. sugar can be grown and produced in a relatively short time period B. sugar may require more energy to produce than it would supply C.

Is it physical change or chemical change when you smooth a wood chair with sandpaper?

Which metal in Period 5 is very reactive and has two valence electrons in each atom? rubidium (RD) strontium (SI) zirconium (Z1) silver (Ag)

Sara and Sam went for a two-hour drive. According to the graph, between. 75 hours and 1.25 hours into their trip, they A) slowed down to a speed of 15km/hour. B) travelled at a constant rate of 30km/hour.

Define the following terms: acids, bases, oxoacids, oxoanions, and hydrates.

Calculate the concentration of a solution that has 6.7 moles in a volume of 0.6 liters.

Is sidewalk cement an element or a compound?