A chemist weighed out 20.7 g of sodium. Calculate the number of moles of sodium she weighed out

helium gas in a 2.00 L cylinder is under 1.12 atm pressure. At 36.5°C that same gas sample has a pressure of 2.56 atm. What was the initial temperature of the gas in the cylinder?

Why are automobiles a contributor to acid rain when there is no sulfur in gasoline to make sox?

Based on Dalton's atomic theory, which of the following is true about all atoms of the same element? They have different masses. They have the same properties. They can be divided into molecules. They are composed of visible matter.

Define ionization energy and explain why the second ionization energy of any element is higher than its first ionization energy.

What is the mass of strontiums isotopes

What is evidence of a physical change. A. ice melts B. silver tarnishes C. biycicle rusts

In a chemical equation, the coefficients represent the ...

How are neutral atoms converted into cations

You weigh three samples of the same metal, and find their masses to be 35.71 g, 39.04 g, and 40.81 g. the corresponding volumes are 3.9 ml, 4.5 ml, and 4.5 ml. what is the density, d, of the metal?

How does adding an iron bar to a solenoid affect the magnetic field of the electromagnet? a. It changes the magnetic field to a current. b. It changes the magnetic field's direction. c. It increases the magnetic field's strength. d.