Jeffrey's Smore Project
Physical and Chemical Property
Physical Property
Physical properties are any properties used to characterize matter and energy and their interactions.
Chemical Property
Chemical properties are properties or characteristics of a substance that is observed during a reaction in which the chemical composition or identity of the substance is changed.
Physical Change
Physical changes are changes affecting the form of a chemical substance, but do not change the chemical composition of that substance. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Chemical Change
Chemical changes occur when a substance combines with another to form a new substance, called synthesis or, alternatively, decomposes into two or more different substances.
Chemical Reactions
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
Conservation of Mass
The law of conservation of mass, also known as the principle of mass/matter conservation, states that the mass of an isolated system (closed to all transfers of matter and energy) will remain constant over time.
Elements & Compounds
Compound
A combination of two or more elements.
Element
a pure substance consisting of one type of atom
- When element properties form a compound it forms a completely new substance. The properties of a compound are the same as the elements that form it. If the properties of the compound separate back to the element, the substance goes back to the original state.
- Compounds can be separated by a chemical reaction. Elements can be separated by physical methods such as heat energy.
- Similarities of elements and compounds: they are both made of atoms, they both have a chemical change, they both can/can't be broken down
- Differences of elements and compounds: An element is made up of only one type of matter, divisible to a single atom with a unique number of protons, neutrons and electrons. A compound is made up of one or more elements.
- A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound.
The chemical formula identifies each constituent element by its chemical symbol and indicates the number of atoms of each element found in each discrete molecule of that compound. If a molecule contains more than one atom of a particular element, this quantity is indicated using a subscript after the chemical symbol and also can be combined by more chemical elements. For example, methane, a small molecule consisting of one carbon atom and four hydrogen atoms, has the chemical formula CH4. The sugar molecule glucose has six carbon atoms, twelve hydrogen atoms and six oxygen atoms, so its chemical formula is C6H12O6.