Atoms and Molecules
The smallest piece of matter that has the properties of an element.
Atom
A process of releasing heat into the environment is called.....
Exothermic
Physical Property
List three examples of a physical property
Color, Density, Mass, Hardness, melting point, boiling point, odor, solubility, conductivity, Magnetism
What is Density?
The positive subatomic particle of an atom is called a...
Proton
A form of potential energy held in the bonds of atoms and molecules is called....
Chemical Energy
A feature of a substance revealed during a chemical reaction such as flammability, oxidation or reactivity is called ...
A Chemical Property
Why is the structure of atoms important for understanding the properties of matter?
All matter is made up of atoms, so understanding how matter is structured allows scientists to determine a substances properties.
Compare mass and weight.
Mass is the matter that makes up any given object and weight is the the gravitational pull on the object. Your mass is always the same but weight changes depending on where your are...(You weigh less on the moon!)
A combination of two or more atoms bonded together is called a...
Molecule
A process that absorbs energy from the environment is called....
Endothermic
The core of an atom is called...
The Nucleus
A substance made up entirely of one kind of atom is called...
An Element
How is a chemical property different from a physical property?
A chemical property is a feature of a substance that is revealed during a chemical reaction. Unlike chemical properties, physical properties are features of a substance that can be observed or measured without changing the chemical structure of a substance.
What is an electron?
The negative subatomic particle of an atom that orbits the nucleus.
Energy in motion is called
Kinetic Energy
A neutron
Water is made up o the elements hydrogen and oxygen. It has 2 hydrogen and one oxygen atom. Hydrogen peroxide is also made up of the elements hydrogen and oxygen. It has 2 hydrogen and 2 oxygen atoms. Given that both molecules are made up of hydrogen and oxygen, why are they different?
The structure and properties of the two molecules are different. The fact that a molecule of hydrogen peroxide has an addition oxygen atom causes it to have different properties from water. For example, hydrogen peroxide is a strong oxidizer and can be used as a disinfectant or bleach, while water does not have these properties.
How can scientists tell if a reaction is exothermic?
An exothermic reaction is a chemical reaction that releases energy into the environment. If the environments temperature increases, it means that an exothermic reaction occurred because energy has transferred into the environment, which is why the temperature increased.
Compare a compound and a molecule. What makes one different from the other?
A molecule is any group of 2 or more atoms chemically bonded together where as a compound is a substance where 2 or more different elements combine. All compounds are molecules but not all molecules are compounds.
What is thermal energy?
The motion of atoms and molecules in substance or object as its temperature increases. The total kinetic energy of all randomly moving particles(atoms and molecules) that make up a substance and it is directly related to temperature.
What is a chemical reaction?
A change that rearranges the atoms of the original substances into a new substance that has different properties from the original substance
Why do glassblowers use torches in their work, and what evidence supports the claim that torches use an exothermic chemical reaction to function?
Glassblowers use torches because they need extreme temperatures to change the glass into various shapes they are designing. The light and heat produced by the torch are evidence that an exothermic reaction has occurred because both light and heat are forms of energy being released into the environment.
If the temperature during the day is 16 degrees celsius and overnight it falls to -9 degrees celsius, by how much did the temperature change?
It decreased by 25 degrees celcius