Characteristics of Chemical Reactions
precipitate
A solid that is deposited from a solution
product
A substance produced during a chemical reaction.
reactant
A substance that takes part in and undergoes change during a reaction
chemical reaction
The process by which one or more substances change to produce one or more new substances with different properties
Rust forming on a piece of iron is an example of a chemical change because a new substance was formed. the evidence is
a color change
Rust forming on a piece of iron is an example of a chemical change because?
a new substance was formed (oxygen bonded with iron)
What is a chemical reaction?
a process where the bonds between atoms are broken and a new arrangement of bonds between atoms is formed.
An unexpected change in _____________ is a sign that a chemical reaction may have occurred.
color
In a chemical process, atoms that make up a substance are regrouped into different ______________ to form new substances with different _______________.
molecules, properties
A _________________ increase or decrease and the production of light are both signs that a chemical reaction occurred.
temperature
Substances giving off a smell, or ____________, while being combined is also an indicator of a chemical reaction.
gas
molecule
The simplest unit of a chemical compound that can exist; formed when two or more atoms chemically combine
atom
The smallest particle of an element; made of electrons, protons, and neutrons
A chemical reaction occurs that involves combining the following reactants: 4 atoms of oxygen, 6 atoms of carbon, and 2 atoms of hydrogen. How many atoms of each element will there be in the product?
There will still be 4 atoms of oxygen, 6 atoms of carbon, and 2 atoms of hydrogen in the product, however they will be rearranged into different molecules.
Identify the five signs of a chemical change.
Unexpected color change Increase or decrease in temperature Precipitate forms Production of light Formation of a gas (bubbles or odor)
How can you tell when a chemical reaction has occurred?
When a new substance has been formed. The signs are production of a gas, light, sound, or color change. A change of temperature (either increase or decrease) is another way to indicate that a chemical reaction occurred.
Which of the following is a chemical change: cutting paper, melting snow, burning logs, carving wood, and/or baking cake?
burning logs and baking a cake
Rust forming on a piece of iron is an example of a
chemical change
A _______________ is a solid substance that forms and separates from a solution and may indicate that a chemical reaction has occurred.
precipitate
In a chemical reaction, when you combine two or more substances called _______, the atoms interact, rearrange, and produce new substances called ________.
reactants, products
