Chemistry: ATOMS, ELEMENTS AND COMPOUNDS Flashcards
what is a physical property?
is a characteristic of a substance that can be observed or measured without changing the identity of the substance.
examples of physical properties
color, hardness, melting and boiling points
What is a chemical property?
is a characteristic of a particular substance that can be observed in a chemical reaction.
examples of chemical properties
flammability, toxicity, combustion.
Qualitative properties
are observed by senses. Examples are color, state, brittleness,
quantitative properties
a property of a. substance that is measurable for example, height, weight temperature, melting point, boiling point.
What is matter
Matter is anything that takes up space
Physical changes
In a physical change the appearance changes but the kind of matter in the substance does not.
boiling point, melting point
chemical changes
in a chemical change the kind of matter changes and one or more new substances with new properties is formed.
examples
combustion
what is the difference between A pure substance and a mixture?
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances.
example of a pure substance
Oxygen
example of a mixture
sea water
what is the difference between a mixture and a solution?
In a mixture, substances are generally just mixed and are not completely dissolved. In a solution, substances are dissolved completely and they cannot be filtered out.
what is an element?
a pure substance that cannot be broken down into a simpler chemical substance.
example: Oxygen
what is a compound?
a pure substance composed of 2 or more different elements that are chemacly joined.
example: table salt
what is a molecule and how does it relate to a compound?
a molecule is a group of atoms bonded together
what is an atom and how does it connect to elements?
An atom is the part of an element.
what are the 7 diatomic elements
hydrogen (H), nitrogen (N), oxygen (O), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).
characterize non metals.
and where are they located on the periodic table?
a non metal is usually a gas or a dull powdery solid that does not conduct heat or electricity.
non metals are located on the right side of the staircase except for hydrogen witch is located in the top left corner.
Characterize metals.
and where are they on the periodic table?
Metals are lustrous, malleable, ductile, good conductors of heat and electricity.
The metals are located on the left side of the stair case.
charactorize metaloids.
and where are they on the periodic table?
metalloids are elements that has properties of both metals and non metals
metalloids are located on the staircase.
what are groups on the periodic table and how are they significant?
they are the vertical column of the periodic table that signifies the number of valence electrons in an element.
what are periods on the periodic table and how are they significant?
are the the horizontal rows in the periodic table that signify the number of electron shells in an element.
what are alkali metals?
an element in group 1 of the periodic table.
what are alkali earth metals?
n element in group 2 of the periodic table.
what are nodal gasses?
an element in group 18 of the periodic table.
what are halogens?
an element in group 17 of the periodic table.
what are similarities between alkali earth metals, alkali metals?
Alkali metals and alkaline earth metals have the following properties: They are relatively soft metals. They are relatively low density metals. They have relatively low melting points