How many grams of He are present in 8.0 L of gas at STP

Which of the following best defines one mole of a substance? Mass, in grams, of each particle of the substance Mass, in grams, of the nucleus of the substance's atoms Amount of substance present in one atom of the substance Amount of substance

A small sack of sand has a density of 1.5 g/cm3 and a mass of 1500 g. How much space (volume) does the sand occupy?

When your heart doesn't know what it wants ... what do you do?

1. When using the equation P1/T1 = P2/T2to relate temperature and pressure of a gas, what must be held constant?2. A sample of gas is held in a capped flask. At 25 °C the pressure is 693 mmHg. What is the pressure of the gas at 37 °C?3.

Select all answers that apply. Which of the following statements depend on the absolute dating of events? A. Dinosaurs went extinct before monkeys evolved. B. Birds separated from dinosaur relatives 120 million years ago. C.

A single electron can have the following set of quantum numbers: n=3, l=2, ml=0, ms = - 1/2. True or False

What shape is the magnetic field produced when current is passed through a wire? a. Parabolic b. Elliptical c. Circular d. Bimodal

What year was the hole in the ozone layer detect in the antarctica?

Sodium (NA) and potassium (K) are in the same group in the periodic table. Sodium is in the 11th position. How many valence electrons does potassium have? A) 0 B) 1 C) 9 D) 11

Which of the following is not caused by the moon? a. moonrise b. tides c. eclipses d. sunrise