A crystallographer measures the horizontal spacing between molecules in a crystal. The spacing is

13.9

nm

. What is the total width of a crystal in millimeters

105

molecules across? Write your answer as a decimal.

The octet rule states that an atom other than hydrogen tends to form bonds until it is surrounded by

How can you tell which end of a molecule is positive and which is negative? How do you label the dipole-dipole relationship?

Hydrogen sulfide decomposes according to the following reaction, 2 H2S (g) → 2 H2 (g) + S2 (g) where ∆S = + 78.1 J/K, ∆H = + 169.4 kJ, which answer describes the entire range of temperatures where the reaction would be spontaneous?

How many argon (ar) atoms are there in 1.5 * 102 g of argon?

The distance light travels in space in a years time

Given the balanced equation representing a reaction: C3H8 (g) + 5O2 (g) = = >3CO2 (g) + 4H2O (g) What is the total number of moles of O2 (g) required for the complete combustion of 1.5 moles of C3H8 (g) ? (1) 0.30 mol (3) 4.5 mol (2) 1.5 mol (4) 7.

What increases in equal steps of one from left to right in the Periodic Table for the elements lithium to neon?

The organisms living together in a community are interdependent upon one another. Look at the food web below. In which of the following ways is a puffin dependent upon salmon? A. Puffins have a commensalistic relationship with salmon. B.

2) Which of the following is a true statement? A: All the atoms of an element must be identical. B: Compounds may be separated by physical means. C: Mixtures may not be separated. D: Homogeneous is one type of compound.

How to tell the difference between ionic and covalent bonding?