Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
42 Cards in this Set
- Front
- Back
|
how did mendeleev arrange his elements |
by atomic mass |
|
|
why did mendeleev leave blanks? |
he predicted that elements will eventually be discovered and fill them per |
|
|
periodic law |
when elements are arranged in increasing atomic number, there is a periodic repetition for their chemical and physical properties |
|
|
what are the three general classifications of elements? |
metals, nonmetals, metalloids |
|
|
properties of metals |
luster, ductile, malleable, current for electricity and heat, solids at room temperature except mercury, silver or gray, cations, 3 or less valence |
|
|
properties of nonmetals |
most are gases at room temperature, poor conductors, brittle, mainly opposite properties of metals. contain 5 or more valence electrons, anions |
|
|
metalloids |
elements that share properties of both metals and nonmetals in certain conditions. |
|
|
alkali metalscon |
Group 1A |
|
|
alkaline earth metals |
Group 2A |
|
|
most reactive |
F/Fr |
|
|
halogens |
located next to noble gases 7A |
|
|
noble gases |
last group, last period, stable with filled orbitals Group 8A |
|
|
representative elements |
elements from group 1A to 7A |
|
|
transition metals |
Group B, all the lower elements and D block. main body |
|
|
inner transition metals |
the two rows below the actual table. |
|
|
atomic radius |
one half the distance between the nuclei of two atoms. |
|
|
why is the internet definition of the atomic radius inaccurate? |
you cannot find the exact location of the outermost electron (Heisenberg) |
|
|
Lothar Meyer |
German chemist that made identical table like Mendeleev |
|
|
cation |
positively charged ion, always smaller. |
|
|
ion |
atom or group of atoms with positive or negative charge. |
|
|
anion |
negatively charged ion, always bigger. |
|
|
ionization energy |
the energy needed to remove an electron in gaseous state |
|
|
generally, the size of cations and anions |
decrease across a period. |
|
|
electronegativity |
the ability of pulling an electron towards the atom when the atom is in a compound. |
|
|
why are noble gases not included? |
they are inert. they are stable and do not form compounds. |
|
|
down a period, atomic radius |
decreases. |
|
|
across a period, ionization energy |
increases |
|
|
across a period, electronegativity |
increases. |
|
|
across a period, nuclear charge |
increases |
|
|
across a period, shielding |
is constant. |
|
|
down a group, atomic size |
increases |
|
|
down a group, ionic size |
increases. |
|
|
down a group, ionization energy |
decreases. |
|
|
down a group, electronegativity |
decreases |
|
|
down a group, nuclear charge |
increases |
|
|
down a group, shielding |
increases. |
|
|
Newlands |
law of octaves, increasing atomic mass with a pattern every 8 elements. |
|
|
Mosely |
Identified atomic number and modern periodic law |
|
|
Seaborg |
Moved inner transition metals to their current spots. |
|
|
element that reacts like a metal and non metal |
H, 1 valence electron |
|
|
iron triad |
Fe, Co, Ni. Create magnetic field. |
|
|
how reactive are the halogens |
most reactive non metal groups |
