7I Earth Flashcards
What are the four different layers of the Earth?
Crust, Mantle, Outer core, Inner core
Which layer of the Earth do we live on?
The crust
What is a tectonic plate?
A large section of crust
Why can tectonic plates cause earthquakes?
Plates get stuck then suddenly release
Describe the properties of the mantle.
Solid, but able to flow like a liquid
What are the Earth’s inner and outer core composed of?
Iron and Nickel
Why is the Earth’s inner core solid?
Intense pressure
What creates the Earth’s magnetic field?
The rotation of the solid inner core within the liquid outer core.
What are sedimentary rocks made from?
Small pieces or grains of rock
If a sedimentary rock contained ripple marks, what environment could it have formed in?
A river or ocean
Give 2 examples of Sedimentary rocks.
Sandstone, mudstone, limestone
What are igneous rocks made from?
Lava (Melted rock)
How does the igneous rock Obsidian form?
Lava cooling very quickly
Why does the igneous rock Granite have very large crystals?
It cooled down very slowly.
How do metamorphic rocks form?
From intense heat and/or pressure
Why don’t igneous or metamorphic rocks contain fossils?
They would be destroyed by the heat/ pressure
What is the rock cycle?
A way to explain how each of the three different rock types form and how they interact with one another
How can a sedimentary rock become a metamorphic rock?
Put it under intense heat and pressure
What will form if rocks are heated until they melt?
Igneous rocks
How can an igneous rock become sediment in a lake?
It is weathered, eroded and transported.
How can a sedimentary rock become an igneous rock?
If it is put under intense heat until it melts and then cools.
Where do metamorphic rocks tend to form?
Deep underground
What causes earthquakes to occur?
Movements of tectonic plates
What is the Sun?
A star
Name one of our closest stars.
Proxima Centauri and Sirius A
What is a galaxy?
A huge collection of gas, dust, and billions of stars and their solar systems.
What galaxy is our planet part of?
The Milky way
What process occurs in stars that allows them to give off energy?
Nuclear fusion
What force keeps planets in orbit around stars?
Gravity
What is in our solar system?
The Sun, the planets and their moons
What is the Hubble telescope?
A telescope in orbit around the Earth
How long does it take for the Earth to orbit the Sun?
365.25 days
Why do we have a leap year every 4 years?
The 0.25 day is added to 1 whole day every 4 years
How long does it take the Earth to rotate once on its axis?
24 hours
Why can it be daytime in the UK but night time in Australia?
The UK and Australia are on opposite sides of the Earth.
What angle is the Earth’s axis rotated at?
23 degrees
What is the barrier between the northern and the southern hemisphere called?
The equator
When it is summer in the northern hemisphere, what season is it in the southern hemisphere?
Only one hemisphere is pointed towards the Sun at a time.
Why is it warmer in summer months?
More of the Sun’s energy is concentrated in a smaller area.
Why do scientists use models?
To represent key ideas and make them easier to understand
Why is the rock cycle an abstract idea?
We cannot see the processes happening
In what types of environments do sediments build up?
In lakes or oceans
