8th Grade Science Final Review

Density

Density is how compact something is.The formula is d = m/vAs temperature increases density decreases.Less dense things float on more dense things.

Mass, Volume and Density

I have snickers with a mass of 8.2 g and a volume of 7.5 mL. What would the density be?

1.1 g/mL

Mass, Volume and Density

What is the density of a gummy bear if the mass is 2.2g and the volume is 1.4 mL

1.6 g/mL

Sink or Float

Liquid Densities:Water 1.0 g/mLMolasses 1.4 g/mLGlycerol 1.3 g/mLOil 0.9 g/mL

Water has a density of 1.0 g/mL. Will glycerol sink or float in water?Sink

Sink or Float

Liquid Densities:Water 1.0 g/mLMolasses 1.4 g/mLGlycerol 1.3 g/mLOil 0.9 g/mL

Will water sink or float in oil?Sink

If I put boil water how does its density change?

It becomes less dense.

Chemical and Physical Changes

The signs of a chemical change are: giving off a gas (bubbling or fizzing), giving off light, temperature change, color change, or forming a solid.

Any other change is a physical change.

Chemical or Physical Change

Cooling water to form ice.Physical change (the temperature change

doesn’t happen on its own).

Chemical or Physical Change

Mixing baking soda and vinegar and it bubbling

Chemical change – giving off a gas

Chemical or Physical Change

Mixing clear phenolthalein with yellow bleach and it turning pink.

Chemical change – color change

Law of Conservation of Mass

Matter cannot be created or destroyed it just changes form. Or

Total matter before a reaction is the same as the total matter after a storm.

C. Total matter is the same before and after a reaction

Earth Science

The Earth is made of four main layers: crust (solid), mantle (solid), outer core (liquid), inner core.

The crust is broken into tectonic plates which are moved by convection currents that are heated by the outer core.

The plates meet at boundaries that are either divergent, convergent, or transform.

Depending on how the plates move different geologic features are formed.

What type of boundary is g?What is a process that happens at g?What is a feature that happens at g?

Convergent (o-c)Subduction, earthquakesVocanos, trenches

What type of boundary is shown?What is a process that happens at the boundary?What is a feature that happens at the boundary?

Convergent o-oSubduction, earthquakesTrenches, volcanos, island arcs

What type of boundary is this?What is a geologic feature made here?Divergent boundaryMid ocean ridge, volcano, rift valley

Put these layers in order from oldest to youngest.

E, D, C, F, B, Fault, A

Put these layers in order from oldest to youngest.

D, C, B, E, Fault, A

Astronomy and Predictable Motions

The movement of the Earth on its axis and around the Sun creates events like days, years, and seasons.

The movement of the moon around the Earth creates events like tides, moon phases, and eclipses.

Stars change through their lives based on where they are at in fusion.

During the main sequence stars fuse hydrogen into helium.

What moon phase is shown below?

1st quarter moon

What moon phase is shown below?

Full moon

What moon phase is shown below?

New moon

What type of Star:

What is a small, medium, or large star called when it is fusing hydrogen into helium?

A main sequence star

What type of Star:

What is a large star called when fusion slows down and it begins to fuse heavier elements?

A red super giant

Which stars have the hottest but dimmest stars?

White Dwarfs

Which group of stars does our Sun belong to?

Main Sequence Stars

Physics and Motions

Energy cannot be created or destroyed but just changes form.

The highest position is always the greatest potential energy.

Motion and speed can be represented in graphs

Which point is the minimum potential energy and the maximum kinetic energy?

6

Which point is there maximum potential energy and minimum kinetic energy?

1