1. The movement of particles from a less crowded area to a more crowded area requires

a. sunlight

b. energy

c. a membrane

d. osmosis

2. What structures allow small particles to cross cell membrane

Pat pours cold, liquid cream into a cup of hot coffee. Which of the following describes how the hot coffee and cold cream will interact? A) The cold cream will drop to the bottom of the cup. When it warms, some of it will rise back to the surface.

Why do fronts tend to create precipitation

Why does food wrapped in aluminum foil keep warm for a long time? A) Aluminum foil is an insulator and prevents heat loss by conduction. B) Aluminum foil forms an air-tight seal and prevents heat loss by convection.

Hydrogen gas + chlorine gas=hydrogen chloride skeleton equation

What does a liquid with more H + ions than water produce? a: pH above 7 b: base c: alkaline d: acid

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

Approximately how many mineral species have scientists identified? 250 5000 1500 60

A compound is 53.31 % C, 11.18 % H, and 35.51 % O by mass. What is its empirical formula? Insert subscripts as needed.

What is the element Ar classified as in the periodic table?