qotd what are the three groups that elements are classified in on the periodic table?
TRANSCRIPT
QOTD
What are the three groups that elements are classified in on the periodic table?
Elements, Compounds, and Mixtures
Mr. Dunnum
Physical Science
Elements
Element- is a pure substance that cannot be separated into simpler substances by chemical or physical means
Pure substance- is a substance in which there is one type of particle
Elements
Each element has its own unique set of properties that allows you to identify it.
You can identify the elements by melting point, density,color, hardness, and sometimes texture
Elements
Elements are classified and grouped according to their shared properties
Metal- are shiny good conductors Nonmetals- dull and poor conductors Metalloids- called semiconductors,
have properties of both metals and nonmetals
Elements to know
Lithium Li
Sodium Na
Potassium K
Rubidium Rb
Cesium Cs
Francium Fr
The Periodic Table
The periodic table arranges and displays all known elements in an orderly way
Each element has its own Chemical symbol
Who discovered the Periodic Table?
In science there are always several scientist who contribute to new discoveries, but the one who received credit for it is Dmitri Mendeleev
Dmitri Mendeleev
Mendeleev first arranged the periodic table in ascending atomic weights and similar properties.
He also left room for the unknown elements and noble gases
After several years of research and many different forms the periodic table, we now have the periodic table we all know
Periodic Table
Periodic table
• Cl is the symbol for chlorine.
The top number is the element’s atomic number.
Tells how many protons in the nucleus
The bottom number is the atomic mass which tells us the average mass of the atom
Isotopes
• Although the number of protons changes from element to element, every atom of the same element has the same number of protons.
• However, the number of neutrons can vary even for one element.
These are called isotopes (I suh tohps), which are atoms of the same element that have different numbers of neutrons.
Isotopes
• An atom’s mass number is the number of protons plus the number of neutrons it contains.
Compounds
A compound is formed when two or more elements are joined chemically.
Once these elements are formed they become a whole new substance
Just like elements compounds have their own set of properties
Ex. H20 Ex. NaCl Ex. C6H6
Compound
Compounds
Breakdown Compounds can be
broken down into simpler substances
The only way compounds can be broken down is through chemical change.
In our worldProteins-build muscle
and helps digest foodCarbon dioxide in
respirationIndustryMedicines, food
preservatives, and synthetic fabrics
Elements to know
Beryllium Be
Magnesium Mg
Calcium Ca
Strontium Sr
Barium Ba
Radium Ra