Science - Chemistry

What is the definition of physical change?

Change in the appearance or form of a substance, does not create something new.

What is an example of physical change?

Ice cream melting, cutting fruit, boiling water

What is the definition of chemical change?

Rearrangement of atoms to form something new. Often an irreversible process.

What is an example of chemical change?

Burning wood, an iron nail rusting, digesting food

How can you tell if a chemical change has happened?

Sound produced, change in colour, gas produced, light produced, change in temperature, solid produced

What is a chemical reaction?

Transforms one set of substances (reactants) into a new set of substances (products).

What is a chemical reaction made up of?

Reactants, products, subscripts, coefficient

What is reactants?

Substances reacting at the start of a reaction

What is products?

Substances produced at the end of a reaction

What is subscripts?

Number placed on the bottom right of an element or compound

What is coefficients?

Number placed in front of an element or compound

What side does reactants go on in a chemical equation?

Left

What side does products go on in a chemical equation?

Right

What is the law of conservation of mass?

It states that matter can be neither created nor destroyed

Which is balanced?

Green

What is the first step when balancing an equation?

Start by counting the number of elements on each side

What is the second step when balancing an equation?

Add coefficients to the elements that aren’t balanced. These can only go in front of the element that is less than the other side.

What is the final step for balancing equations?

This changes the numbers. Need to just do one final check

What do you do if you do all three steps for balancing equations but it still isn’t balanced?

Sometimes this changes the amount of other elements too. So you may have to keep adding more coefficients until all are balanced. Before doing final check.

What are two different types of metals when classifying metals?

Native metals, and ores

What are native metals?

Non-reactive metals found naturally in their elemental form

What are ores?

Reactive metals found naturally as compounds

When extracting metals, what is their reaction to carbon?

Reacting metal oxides with carbon removes oxygen from the metal ore. Occurs at high temperatures

When extracting metals, what is electrolysis?

Involves passing an electrical current through a molten (liquid) form of impure metal. Only used to extract reactive metals

What is the principles of green chemistry?

Design of chemical products and processes that eliminate the use or production of hazardous substances