Which measurement of length is the smallest?

A. 9 * 10 ^-6

B. 7 * 10^-5

C. 7 * 10^1

D. 9 * 10^2

Calculate to the correct number of significant figures: (24.6681 x 2.38) + 332.58

What is the pH of a 0.0025M HCI solution?

Which hypothesis of Thomson's atomic model was later found to be not true by Niels Bohr and why?

What is the difference between a sodium atom (Na) and a sodium ion (Na1+) ?

Joe and Angie are studying how listening to music affects grades. Joe listened to music while he studied while Angie studied in silence. After two weeks, they took the same math test and Joe scored higher than Angie.

Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: 2H2O2 (l) → 2H2O (l) + O2 (g) ΔH = - 196 kJ Calculate the value of q (kJ) in this exothermic reaction when 3.

What is the concentration of hydronium in each of the following cases: [OH-] = 10-12 M? [OH-] = 10-2 M?

Which statement best explains why elements are matter? An element is a physical substance that has mass and takes up space. Elements are pure substances that cannot be divided chemically. Each element is a pure substance composed of one type of atom.

Which of the following best describes what causes the phases of the moon? The alignment of the sun, Earth, and moon The speed of the moon around the Earth The speed of the Earth around the sun The alignment of the planets

At which temperature would atoms of a He (g) sample have the greatest average kinetic energy? (1) 25°C (3) 273 K (2) 37°C (4) 298 K