Atomic Structure And The Periodic Table Flashcards
Why was mendaleev able to make the periodic table when others couldn’t
He listed the elements in order of atomic mass. Other chemists had done this but he sometimes broke the rule to make elements match up with others with similar properties. He also left gaps where undiscovered elements would later fill.
What is atomic mass based aroun
Carbon-12 6protons 6 neutrons and 6 electrons.
What are the rows and columns in a periodic table called
Rows are called periods
Columns are called groups
Why is the atomic mass of Cl 35.5 rather than 35
As there are two isotopes, one with a ram of 37 and the other of 35 and 75% are 35 and the rest are 37
7535)+(2537). 3550
—————– = ________ = 35.5
(75+25). 100
What is the electronic configuration
The way electrons are configured around the nucleus of an atom
What are rules for electron configuration in atoms
First shell only has 2 electrons
The next shells have a max of 8 electrons, then a new shell is filled
The number of electrons in the outer shell usually is the same as the group it’s in
What is the electron configuration of an element with 25 electrons
2.8.8.7
What are cations
Positively charged atoms that have lost electrons meaning they have more protons than electrons.
What are anions
Ions that have gained electrons. They are negatively charged as they have more electrons than protons.
Why is an ionic bond
Strong electrostatic force between opposite charged ions such as between Na+ and Cl- to make NaCl
What are ionic compounds
Compounds made of more than one ion such as aluminium oxide
Al2O3
What are compound ions
Ions made of several elements such as the nitrate ion
NO3-
What is a lattice structure
A regular structure in which ionic compounds are arranged
What are the conductive properties of ionic compounds
When they are solid they don’t conduct. When they are molten or in aqueous solutions, they conduct electricity
