Summary
Summary Biology Edexcel A-level Topic 1
- Institution
- PEARSON (PEARSON)
Summary of topic 1 Biology Edexcel A Level- with complete notes!
[Show more]
Seller
Follow
Content preview
**Chemistry behind water molecules**The electrons that are shared between the oxygen atom and the hydrogen atoms in a water
molecule has the oxygen atom having a greater pull of the electrons making it slightly
electronegative than hydrogen.
- Hydrogen being slightly positive means that water is a polar molecule (dipole)
- Hydrogen bonds are formed between the water molecules because of the forces of
attraction between the slightly positive and slightly negative parts of the molecules
Physical properties of Water
**HIGH SPECIFIC HEAT CAPACITY**
- The hydrogen bonds in the water give the water a high stability meaning that it has a high
specific heat capacity. It requires a lot of energy to raise the temperature of the water
- This is an advantage as it allows the stability of an aquatic environment
Also it is good for cooling: large amounts of heat is required to evaporate water.
**ICE IS LESS DENSE**
- Water in solid form, is less dense than water in liquid form.
- The molecules expand as they are held apart due to the semi crystalline structure formed
from low levels of kinetic energy.
- The surface of water, in cold temperatures, have an icy solid layer surface due to the low
density of ice in comparison to water
This keeps organisms underneath alive
**COHESIVE**
- Water is cohesive
- Cohesion meaning that the molecules in the substance have a tendency to stick to each
other due to the hydrogen bonds
- This is useful in the transport of water in the xylem of plants
Also a high surface tension allowing small insects like pond skaters to glide along the water
**GOOD SOLVENT**
- Water is a good solvent because it is polar: it can break apart ionic bonds between ions
and can interact with charged regions of a molecule and dissolve the substance
- It is a good medium as it is liquid in a wide range of temperatures
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
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 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 mitzharquisola1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £8.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53068 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now