The Guys behind it all
Where is all the mass in an atom?
in the nucleous
What is always the same in atoms of the same element?
The number of protons (and thus electrons)
In what order are elements placed on the Modern Periodic Table
In order of Increasing Atomic Number
What's the maximum number of electrons the INNER electron shell can hold?
Who is known for creating the periodic table?
Mendeleev
Which subatomic particle is positively charged?
A proton
Explain what is meant by Hydrogen-1 and Hydrogen-2
They are isotopes, H-1 has a mass of 1, H-2 has a mass of 2. They both have 1 proton because they are both Hydrogen
What are the columns and rows of a periodic table called?
columns are GROUPS
rows are PERIODS
Except for the INNER Shell, what is the maximum number of electrons an electron shell can hold?
8 electrons
In what order did menedleev put the elements?
In order of increasing weight (Mass)
What is the mass of an electron ?
Almost Zero
(or a tiny fraction approc 1/2000)
(or negligible mass)
Do isotopes have the same chemical properties? explain
Yes: because they are atoms of the SAME element (same number of protons and electrons)
What does the Atomic Number tell us?
The number or protons
What is the electron configuration of an atom with 12 electrons?
2,8,2
What TWO things did Mendeleev do after ordering the elements when creating his periodic table?
He put elements in groups of similar properties, leaving gaps for undiscovered elements
In an ATOM, what do we know about the number of protons and the number of electrons?
They are the SAME
Why is the Relative Atomic Number (RAM) often a decimal number?
Because it is the AVERAGE of all the isotope basses (based on their abundance)
How do you determine the number of neutrons given the Atomic number and the Mass number?
Mass Number MINUS Atomic Number
What is the electron configuration of an atom with 20 proptons?
2,8,8,2
Mendeleev swapped two elements so they fitted better in to their groups of similar properties. Which two elements did he swap?
Tellurium and Iodine
Why are atoms neutral?
They have the same number of positive protons as they have of negative electrons.
The positives and negatives cancel each other out.
What is an isotope?
An atom of the same element, with the same number of protons but different number of neutrons
What are the most reactive metals called? what group are they in?
Alkali metals in group 1.
For an atom with electron configuration 2.8.7. How many electron shells does it have? How many electrons are in the outer shell? How many protons does the atom have?
3 electron shells
7 outer electrons
17 protons