Unit 1- Chemistry Flashcards
(98 cards)
What are elements?
Pure substance that cannot be broken down into a simpler substance. Eg. Carbon, oxygen, and iron
What is a compound?
Pure substance made from two or more elements that are combined together chemically. Eg. Water, salt and ammonia.
What are physical properties?
Characteristics of a substance that can be observed or measured. Eg. Texture ( fine, course, powder, granular)
Odour (sweet, sour, acrid, smoky)
Malleability ( hammered into sheets)
What is a chemical property?
Ability of a substance to change into a new substance or substances. Eg. Flammability, toxicity and corrosion
What is matter?
Matter is anything that has mass and takes up space. Matter makes up everything around us.
What are the 5 particle theory of matter?
- All matter is made up of extremely tiny particles.
- Each pure substance is made up of its own kind of particle, different from other pure substances.
- Particles attract each other.
- Particles are always moving.
- Particles at high temperatures move faster on average than particles at low temperatures.
What would the solid state look like?
Molecules are “stuck” together.
Molecules are vibrating back and forth but are keeping their positions.
They have their lowest energy when they are in the solid state.
Their shape does not change when the container is tilted.
What does the liquid state look like?
Molecules are spread out slightly but touching.
They are vibrating back and forth faster than when in the solid state and they are moving past one another.
Higher energy than in the solid state.
They take the shape of the bottom of the container and have a horizontal top surface.
They can be poured.
What does the gas state look like?
Molecules are far apart and flying around colliding with each other and the walls of the container.
Molecules are moving fastest and with highest energy when in the gas state.
They spread out to take the shape of the entire container.
They can be poured.
What is a pure substance?
Its a homogenous composition and is the same throughout.
What is an element?
An element is made up of one type of particle/atom and can’t be broken down further. Eg. Gold, oxygen and mercury.
What is a mixture?
It has at least 2 kinds of particles or substances and it can be mechanically separated into pure substances.
What is a solution?
Homogeneous composition Particles are uniformly scattered Can't see different parts (particles too small to see) Transparent (can see through it) Composed of a solvent and a solute
What is an mechanical mixture?
It’s a heterogeneous composition, not uniform throughout and usually can see different parts/components
What is a suspension?
Particles can be seen with the naked eye or a low power microscope and gravity will cause the suspended particles to separate over time.
What is an ordinary mechanical mixture?
Different components are large enough to see with the naked eye.
What is colloids?
Homogeneous in appearance Tiny particles that can't be seen with a microscope Particles won't settle May show Tyndall effect Usually opaque
What is qualitative?
Is a description of the substance or change that is not measured. Eg. Blue, granular, dissolved, reacted
What is Quantitative?
Is a description of the substance or change that is measured and involves a value. Eg. B.P. Is 10 C, mass= 113g
What is a physical change?
A change that does not result in a new chemical substance being formed. Changes may be reversed. Eg. All changes of state, changing the shape or size of the substance, dissolving the substance
What is a chemical change?
Results in a new substance being formed that has different properties.
Look for’s: hard or impossible o reverse, colour change, heat or light given off or absorbed, starting substance used up, bubbles form in a liquid, precipitate forms in liquids. Eg. Cooking, burning, corroding and reacting
What is an atom?
Smallest part of an element that has all of the element’s properties. Eg. Atoms of copper are not the same as atoms of iron.
Classify sugar and water
It’s a solution because you can’t really see the sugar particles with a naked eye and the sugar is transparent.
Classify beach sand.
It’s an ordinary mechanical mixture because you can see all the different parts with your naked eye.