Which of the following measurements is expressed to three significant figures? 7.30 * 10-7 km 0.007 m 7077 mg 0.070 mm

Liquid water freezes into ice, it looks different. why is this not a chemical change

A solution is prepared by dissolving 76.3 g NaI in 545 g of water. Determine the mole fraction of NaI if the final volume of the solution is 576 mL.

Which of these is a mixture? a. oxygen b. air c. carbon dioxide d. carbon

Metallic magnesium reacts with steam to produce magnesium hydroxide and hydrogen gas. a. If 16.2 g Mg are heated with 12.0 g H2O, what is the limiting reactant? b. How many moles of the excess reactant are left? c.

When equal moles of each reactant are used, which type of reaction will produce a slightly basic solution? strong acid - strong base strong acid - weak base weak acid - strong base None of these are correct.

Find the de Broglie wavelength (in nm) associated with an electron that is moving with a velocity of 5230 km/s. The electron rest mass is 9.11 x 10⁻³¹ kg.

Baby Caitlen is about to turn one year old. She loves to play peek-a-boo and acts so surprised each time a hidden face appears behind her dad's hands. Why is she surprised?

8. What is an energy level? A) The region outside the nucleus where the neutron is likely to be moving. B) The region outside the nucleus where the electron is likely to be moving.

In alpha decay, alpha particles are ejected from the nucleus. Which equation represents alpha decay? 241Am 23Np + 4He 18F → 180 + °C 14C → 14N+_e 152 Dy → 15. Dy+y

In a study of the conversion of methane to other fuels, a chemical engineer mixes gaseous methane and gaseous water in a 0.778 L flask at 1,072 K. At equilibrium, the flask contains 0.206 mol of CO gas, 0.187 mol of H2 gas, and 0.187 mol of methane.