Physical And Chemical Changes Flashcards
What happens in a chemical change?
Chemical bonds are made or broken
What happens in a physical change?
Chemical bonds do not change
What is the transition between a solid and a liquid called?
Melting
What is the transition between a liquid and a gas called?
Evaporating
What is the transition between a liquid and a solid called?
Freezing
What is the transition between a gas and a liquid called?
Condensing
Is frying an egg a physical or chemical change?
Chemical
Is a bike rusting a physical or chemical change?
Chemical
Is food dye changing the colour of water a physical or chemical change?
Physical
Is digestion in the stomach by stomach liquids a physical or chemical change?
Chemical
Is melting ice cream a physical or chemical change?
Physical
Is fruit ripening a physical or chemical change?
Chemical
Is burning a match a physical or chemical change?
Chemical
Is fireworks exploding a physical or chemical change?
Chemical
Is dissolving sugar in water a physical or chemical change?
Physical
Are chemical changes usually reversible?
No
Is a glass bottle smashing a physical or chemical change?
Physical
Fill in the blanks: A __________ is a long molecule made up of many smaller identical molecules (called monomers) bonded together.
Polymer
Fill in the blanks: Corrosion is a type of chemical reaction between a __________ and substances in its environment that results in the metal being ‘eaten away’. The most common form of corrosion that we encounter is the corrosion of iron, a process referred to as rusting. Over time, rusting can cause enormous damage to buildings, bridges, ships, railway tracks and cars.
When iron reacts with __________ and oxygen in the air it forms iron __________ and other iron compounds that make up the familiar red-brown substance known as rust.
Some substances in the environment make the rusting reaction happen much more quickly. One of the most effective of these is __________. Steel dinghies that are used in the ocean rust much faster than those that are used only in fresh water.
Metal
Water
Oxide
Salt
Fill in the blanks: There are a number of factors that can be changed in order to alter the speed of a chemical reaction.
The following descriptions show how we can speed up a reaction:
The __________ is increased (this means the reactant particles will be moving around faster)
The __________ of a reactant is increased (this means that there will be more particles to react)
The __________ area is increased (this means a greater number of reactant particles are exposed)
A __________ is used (although this is not used up in the reaction it causes it to happen faster)
Temperature
Concentration
Surface
Catalyst
Which of the following observations are good indicators that a chemical reaction may have occured?
A new substance is formed
The temperature of the substances changes spontaneously
A colour change occurs
Bubbles appear
A flame appears or light is produced
A precipitate forms
Substances mix together
A substance melts
A larger substance breaks down in to smaller ones
A new substance is formed
The temperature of the substances changes spontaneously
A colour change occurs
Bubbles appear
A flame appears or light is produced
A precipitate forms
