Thursday 25 February 2016

Explaining Precipitation

Today, we got to mix solutions together to see if a precipitate formed. Then, we wrote a word equation for the reaction and used this to word out what the precipitate was (if one formed).

If there was no precipitate, this means the ions were all more attracted to water than with each other.

The Solubility Rules (below) are given to us. These are really useful for working out what does form a precipitate (insoluble) and what does not form a precipitate (soluble).






Wednesday 24 February 2016

Precipitation Reactions - An Introduction

Today, we were introduced to a special type of reaction called precipitation. This is where you combine two solutions, and a solid (precipitate) is formed. The example we looked at was adding Iron (III) Nitrate to Sodium Hydroxide. A brown precipitate formed; this was called Iron (III) Hydroxide:


Then, we were given a solution and added Sodium Hydroxide to that. We had to create a diagram like the one below to show what happened:



Here is a video of some of these concepts being taught to another class:

Monday 8 February 2016

Earthquakes!!

After learning that fault lines can be the sites of earthquakes, we will be spending this week learning about what earthquakes actually are.

  • What causes them?
  • Why can the be so destructive?
  • What are aftershocks?
  • Why does liquefaction sometimes occur?
This is a really good link, too: http://sciencelearn.org.nz/Contexts/Earthquakes/Science-Ideas-and-Concepts

This video gives a good overview of what we will be looking at in class:



Focus and Epicentre

What happens within/along the fault line to actually trigger an earthquake?

Earthquake Waves

There are four different types of earthquake waves: two body waves, called P (Primary) and S (Secondary) Waves; and two surface waves called L (Love) and R (Raleigh) Waves. What are their characteristics?


One thing Mr Nicoll forgot to mention in this video was the link between the Richter Scale, Modified Mercalli Scale and the waves:

Richter Scale measures magnitude. This is the amount of energy in each wave pulse. This means each wave has a larger amplitude.

Modified Mercalli Scale measures intensity. This is the frequency of the waves. The higher the frequency, the more seismic waves per minute.'

Aftershocks

One common occurrence after earthquakes is a series of aftershocks. Are these just more earthquakes, or are they something slightly different? Why do they occur?

Liquefaction

In certain soil types, liquefaction is something earthquakes can cause. It can be devastating. What type of soils are susceptible to liquefaction? How and why does it happen?

Tuesday 2 February 2016

Fault Lines

Our first goal for this unit is to be able to explain how fault lines form.

Earth's Structure

The first step is to understand the structure of Earth, beneath the surface (which we can see). This interactive website was used to help learn some of the key parts:

SOURCE: https://en.wikipedia.org/wiki/Structure_of_the_Earth

Plate Tectonics

Thursday's lesson was about tectonic plates:


This video shows some simple models of Convection Currents in the Mantle, and how these make the Tectonic Plates move. If they collide, they often cause Fault Lines and Fold Mountains to form.


Faults