6th - Science Chapter 5 notes Flashcards
(56 cards)
***Over thousands of years, what breaks up rocks into smaller pieces?
Weathering
***The chemical and physical processes that change objects on Earth’s surface over time are called?
Weathering
***Physical processes break rocks into smaller pieces, during what?
Mechanical Weathering
Mechanical weathering does not change the what of the rock?
Chemical makeup
When mechanical weathering breaks a large rock into smaller pieces, the total what of the rock increases?
Surface area
Between sandy and clay soils, which soil holds more water and nutrients because it consists of smaller particles that have more surface area?
Clay
***Water enters cracks in rocks and freezes in what? Water does what when it freezes and makes the cracks larger?
Ice wedging; expands
***Grinding rock away by friction or impact is called what?
Abrasion
***What growing in a crack in a rock and animals burrowing through loose rock can cause mechanical weathering?
Plants
***The materials that make up rocks are changed into new materials during what?
Chemical Weathering
***Water is an important agent of ______________ weathering because most substances ___________ in water.
Chemical; dissolve
***What is a more powerful weathering agent then water?
Acid
***The measure of acidity is called what?
pH
***An acid has a pH less than what?
7
***Rain weathers rock because rain is slightly what?
Acidic
**What type of rain contains pollutants that make its pH less than 5?
Acid rain
***Oxygen combines with other elements or molecules during what?
Oxidation
Most oxygen used in oxidation comes from where?
The air
***What is the product of oxidation?
Oxide
Oxides are useful because they form ___________, which people use to obtain metals.
Ores?
What part of a rock oxidizes the most because it has more contact with oxygen in the air?
Outer layer
***Mechanical and chemical weathering depend on ____________ and temperature.
Water
***Mechanical weathering occurs fastest in areas that have a lot of ___________ changes.
Temperature
***Chemical weathering is fastest where the climate is warm and _________.
Wet