Periodic Table of Elements
Who created the first periodic table and how did he do it?
Dmitri Mendeleev created the first periodic table and arranged the elements in order of atomic mass and the elements occurred in a periodic or regularly repeating pattern
What subatomic particles are atoms made up of?
What are the charges of the particles and where are they located in the atom?
Protons, Neutrons, and Electrons
Protons= Positive charge+ located in the nucleus
Neutrons= no charge, located inside the nucleus
Electrons= Negative charge- located in shells which represent different energy levels.
What are metallic elements usually known for?
Their conductivity
What is a short way of writing a compound?
By writing a formula
Who revised Mendeleev's periodic table and how did he do it?
Henry Moseley revised Mendeleev's periodic table and he arranged the elements on the table in order of increasing number of protons, or atomic number
What is a molecule and what is the smallest part of an element
A molecule is two or more atoms bonded together and an atoms is the smallest part of an element
How many atoms does one molecule at least have?
2
What is a compound?
Two or more different kinds of atoms linked together
1- where does the chemical name of the elements come from?
2- Describe where and what the atomic number is.
1- They come from many different sources.
2- The atomic number is the number at the top of the square and it is the number of protons in the nucleus of an atom of that element. All atoms of an element have the same atomic number
Fill in the blank
The atomic ______ equals the number of protons and neutrons in the nucleus of an atom
number
Where did the atoms of molecules come from?
The atoms of a molecule come from two or more elements
What two things does a formula tell us?
1. The elements that are in a compound
2. The number of atoms of each element that are in 1 molecule of that compound
1- What is a column of elements called and does the column go horizontal or vertical? Also, include an important fact!
2- What is a row of elements called and is the row of elements horizontal or vertical?
1- The column of elements go vertical and they are called groups or families. Elements in the same group often have similar physical and chemical properties.
2- The rows are called periods and are horizontal
How do you find the number of neutrons in the atom?
Subtract the atomic number/protons from the rounded atomic mass
Are there more or fewer elements than compounds and are molecules larger or smaller than atoms?
Fewer and larger
What is involved to separate compounds?
A lot of energy like heat, light, and electricity, is involved to make or separate a compound
Where are metals, non-metals, and metalloids found on the periodic table and give some descriptions of each?
Metals - elements to the left side of the zig-zag line. They are elements that are shiny and conduct heat and electricity well
Nonmetals - Elements to the right of the zig-zag line. They are often dull and brittle and are poor conductors of heat and electricity
Metalloids - Border the zig-zag line on the periodic table. They have properties of metals and some of nonmetals.
Electrons travel in energy levels/shells how many electrons should there be in the 1st,2nd,3rd, and 4th energy level/shell?
(K)1st - 2
(L)2nd - 8
(M)3rd - 18
(N)4th - 32
1- what is a short way of writing an element?
2- Can you tell how many atoms there are in a molecule when looking at the formula?
1- formula
2- yes
True or false
Properties of a compound are different from the properties of the molecules that form them
False
Properties of a compound are different from the properties of the molecules that form them
molecules should be elements