Summary Grade 9 Social Sciences (SS) (Geography & History) Term 3 (Via Africa) Summaries
4 views 0 purchase
Course
Social Sciences
Institution
9th Grade
This product contains all the work for Social Sciences (Geography & History) Grade 9, term 3 – based on the “Via Africa” textbook in English.
Geography – Surface forces that shape the earth
Unit 1: Weathering
Unit 2: Erosion and deposition
Unit 3: The impact of people on soil ...
,
, Impact of human activities on weathering Concept of weathering
• Burning fossil fuels. • Weathering = the processes that break down rocks, soils
• Dynamite blasting. and minerals into smaller pieces through contact with
• Mining operations. the atmosphere, biota and water.
• Quarrying. • Responsible for soil creation and unique features on
Earth.
Biological weathering U1:
•
Physical weathering
Biological weathering = the physical and Weathering
chemical actions of living things. • Physical weathering = the breakdown of rocks
• Physical actions include rock breaking through into smaller components without altering their
plant root growth or animal burrows. chemical composition.
• Chemical actions involve the excretion of acids, • Granular disintegration - rocks break up into
which can weather rocks and minerals. small grains to form sand or small pieces of
• Decomposition of organic matter releases gravel.
corrosive substances into the environment. • Exfoliation - rocks peel off in sheets.
Chemical weathering • Block separation - rocks break up into large
fragments related to rock joints.
• Chemical weathering = the breaking of rocks into particles
with different mineral compositions from the original rock.
• Solution weathering - minerals or soluble chemicals in the
rock dissolve directly in water.
• Hydrolysis - minerals in the rock react with hydrogen in
rainwater.
• Oxidation - results in red or yellow oxides or hydroxides
produced when rock minerals react with dissolved oxygen.
• Hydration - minerals in rocks absorb water, expand and
break up.
• Carbonation – a weak solution of carbonic acid is formed
when carbon dioxide dissolves in water.
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller SummariesSA. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.98. You're not tied to anything after your purchase.
