Which of the following is an example of a chemical change?

a. ice melting

c. pounding gold into a coin

b. milk souring

d. a puddle of water evaporating

A system is a group of related parts with specific roles that work together to achieve an observed result. Seeds, soil, a plow, and a large field are parts of what type of system? A. an agricultural system B. an organ system C. a legal system D.

Sulfur trioxide, SO3 (g), reacts with water to form sulfuric acid, H2SO4 (g), a major component of volcanic smog. What is the balanced chemical equation for this reaction?

Which compound has the smallest molar mass? A) CO2 B) CO C) H20 D) NaOH

A solution with a higher concentration of hydroxide ions (oh-) than hydrogen ions (h+)

10. How were scientists able to discover the Buckyballs in space?

How does food in a fridge cool down

How many electrons would be found in the ion whose symbol is given below? N3-

In an atomic model that includes a nucleus, positive charge is a. located in the space outside the nucleus. b. spread evenly throughout an atom. c. concentrated at multiple sites in an atom. d. concentrated in the center of an atom.

In the Table of Atomic Particles, various symbols have two numbers. The top number represents the atomic mass of the particle, what do the bottom numbers represent? Select all that apply.

A chemist is working on a reaction represented by this chemical equation: FeCl2 + 2KOH → Fe (OH) 2 + 2KCl. If the chemist uses 4.15 moles of iron (II) chloride and 3.