Elements And Compounds Flashcards
By asking these questions scientists can classify matter into:
Mixture, element, compound
two or more substances that are not chemically combined with each other and can be separated by physical means. The substances in a mixture retain their individual properties
Mixtures
a special kind of mixture where one substance dissolves in another.
Solutions
simplest form of pure substance. They cannot be broken into anything else by physical or chemical means
Elements
pure substances that are the unions of two or more elements. They can be broken into simpler substances by chemical means.
Compounds
Can it be separated by physical means?
If the answer is no, the matter is a
pure substance
There are more than one hundred known _______ in the universe listed on the periodic table of elements
Elements
Atoms of the same element are _____
Alike
Atoms of different elements are ______.
Different
An element is a substance that is made from one kind of atom only. It _______ be broken down into simpler substances
Cannot
In _____, a system of representing elements with symbols was introduced.
1813
Each symbol consists of ___ or ____ letters
1 or 2
Currently there are _____ known elements, most are ______.
118, metals
The first letter of an element symbols is always (blank) and second one and the third letters, if present, are in (blank blank).
capitalized, lower case
is a useful way to arrange elements
The Periodic Table
The vertical columns are called
groups
The horizontal rows are called
periods
Elements in the ______ group have _____ properties
Same, similar
Three quarters of the elements are
metals
One quarter of the elements are
non-metals
Aluminum
Al
Bromine
Br
Calcium
Ca
Carbon
C
