Weathering 1

M. Poarch – 2005 http://science-class.net

Name_____________________________________

Weathering

SAFETY FIRST! GOGGLES ARE REQUIRED DURING

THIS INVESTIGATION! Background Information: Weathering is defined as the group of destructive forces that change the physical and chemical character of rock near the earth’s surface. Mechanical or physical weathering is the breaking down of rocks into smaller pieces. The change in the rock is physical with little or no chemical change. Examples of mechanical weathering include: frost action, abrasion, and pressure release. Chemical weathering is the breakdown of rock from exposure to water and atmospheric gases (usually carbon dioxide, oxygen, and water vapor). As these agents break the rock, new chemical compounds form. Examples of chemical weathering include: rusting, acid breakdown, and solution weathering. Questions:

1. What is the effect of water on limestone? 2. What is the effect of acid on limestone?

Hypotheses:

1. If ___________________________________________________________________,

then _________________________________________________________________.

2. If ___________________________________________________________________,

then _________________________________________________________________.

Materials:

2 small pieces of limestone Two beakers Water

Dilute HCl Goggles Graduated cylinder