beginner
Give an example of: a release of gas.
some examples are: baking soda & vinegar= CO2, baking soda & lemon juice=CO2. (ect.)
Give an example of: Sudden rise in temperature.
example: Fireworks (ect.)
Give an example of: change in color.
example: Rusting of iron turns it from silver-gray to reddish-brown.
Give an example of: Energy being released (in the form of heat, light, or sound).
example: the heat and light from a burning candle or match.
Example of: a chemical change
examples: rotting, burning, rusting. (ect.)
Define: Chemical Change.
a chemical change is when two substances are exposed to each other, therefore changing the "identity", or chemical composition of the elements, or creating a new substance form the two reacting.
what is the difference between chemical and a physical change?
In a physical change, the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
what is aqnother way of saying 'chemical change'
chemical reaction
can chemical changes be reversed?
NO!
is digestion AND cooking a chemical change?
yes.
what causes a chemical reaction to take place?
chemical bonds between atoms that are formed or broken.
how does temperature affect chemical changes?
increasing the temperature will cause chemical changes to occur faster.
what are some examples of chemical changes that happen in our daily life?
Digestion,cooking, and combustion.
Define: combustion.
rapid chemical combination of a substance with oxygen, involving the production of heat and light.
why are chemical reactions so important?
because they allow living things (cells, animals, people, insects) to grow, develop, reproduce, and adapt.
Why is it called a chemical change?
because it is a change of materials into another, new materials with different properties and one or more than one new substances are formed.
why is burning considered a chemical change?
because as a result of burning, ash is formed as a new chemical substance.
is freezing & boiling a chemical change?
YES
what is exothermic? what is endothermic?
exothermic is a reaction which gives off heat, and endothermic absorbs heat(like photosynthesis).
what would happen if there was no chemical reactions?
Without chemical reactions, nothing would ever change. Atoms would stay atoms. New molecules wouldn't form. No organisms could live.
what is the main 'purpose' of chemical changes?
to produce most of our energy.
where is chemical energy "stored"?
in the bonds of atoms and molecules.
what is a pure substance?
The substances that are free from any kind of mixture and contain only one kind of particle are considered 'pure'.
why do some chemical reactions stop at some point?
When there is not enough of one reactant in a chemical reaction, the reaction stops.
what substance cannot be broken down?
an element