Why phosphorus forms 3 bonds in molecule such as PH3 and PCl3-

Calculate the Mr of MgO

The magnitude of a force is

A light microscope would be most advantageous for viewing which of the following? a. small molecule such as water b. a DNA strand c. virus d. eukaryotic cells such as green algae

How many moles of water were lost if the amount of water lost was 0.406 grams? Do not include units and assume three significant figures in all numbers. Be sure to include the zero before the decimal if the number is less than one.

Which is one way that scientists ensure that data is reliable?

As the temperature of a reaction increases, it is expected that the reacting particles collide

Consider this balanced chemical equation: 5SF4 + 2I2O5 = 4IF5 + 5SO2 a. What is the limiting reagent when 4.687 grams SF4 reacts with 6.281 grams I2O5 to produce IF5 and SO2.

Under what conditions would you take samples of vomitus, sputum, and serum creatinine? a. when external contamination is suspected b. when internal contamination is suspected c. when you need to locate contaminated areas d.

A piston system absorbs 50.5 J of energy in the form of heat from the surroundings. The piston is working against a pressure of 0.491 atm. The final volume of the system is 56.2 L.

A vertical piston-cylinder device contains water and is being heated. During the heating process, 70 kJ of heat is transferred to the water, and heat losses from the side walls amount to 8 kJ.