A helium balloon contains 16.9 L of helium at STP. How many atoms of helium are in the balloon

How many kilocalories of heat are required to raise the temperature of 225 g of AL (Cal = 0.21 cal/gC) from 20.0 C to 100 C

Suppose you are asked to find the area of a rectangle that is 2.1-cm wide by 5.6-cm long. Your calculator answer would be 11.76 cm2. Now suppose you are asked to enter the answer to two significant figures.

Which describes Bohr's contribution to the atomic model? A. He described electrons in specific orbits around the nucleus. B. He determined that atoms are neither created nor destroyed. C. He recognized that an element could have several isotopes. D.

Write the net ionic equation for the reaction that occurs when 0.103 mol HBr is added to 1.00 L of the buffer solution.

What do periods on the periodic table represent?

WHY IS THE OCEAN SALTY ALSO I CANT TAKE OF CAP LOCKS ON A CROME BOOK

Compare and contrast steak and juice

Which of the following laboratory tools would be most appropriate for determining the volume of and irregular shape A) ruler B) triple beam balance C) graduated cylinder D) answers b and c

What type of change is the process of photosynthesis

A graduated cylinder is filled to the 40.00-mL mark with a mineral oil. The masses of the cylinder before and after the addition of the mineral oil are 124.966 g and 159.446 g, respectively. In a separate experiment, a metal ball bearing of mass 18.