What are some examples of endothermic reactions?

A helium balloon can hold about 6.8mol of the gas. Assuming the balloon is kept at room temperature (25°C) and has a maximum volume of 1.2 liters, what is the pressure inside the balloon?

Why do girls develop differently?

Which is a chemical change A ice melting B ice being carved C. water boiling D water breaking down into hydrogen and oxygen

120.0J of energy are added to a sample of air with unknown mass. The sample increases its temperature from 33.2°C to 45.0°C. What is the mass of the air sample? (c=1.0 J/g°C)

What is the percentage error of a length measure of 0.229 cm if the correct value is 0.225 cm

What did scientists observe using the earliest microscopes

Which statement describes the redox reaction that occurs when an object is electroplated? A. It is spontaneous and requires an electric current. B. It is spontaneous and produces an electric current. C.

How are electromagnetic different than all other waves

Find the ratio of speeds of an electron and a negative hydrogen ion (one having an extra electron) accelerated through the same voltage, assuming non-relativistic final speeds. Take the mass of the hydrogen ion to be 1.67*10^{-27} kg.

A type of rock that undergoes changes because of heat and pressure