Periodicity
What is the Law of Octaves?
Elements were arranged in groups of 7 and every 8th element had similar properties. Mass and chemical properties
how many groups and periods are there and which is vertical and which is horizontal?
group = vertical column = 18
period = horizontal rows = 7
what is the trend for atomic radius?
increases left and down
what is group 1 called and what are some characteristics?
alkali metals and soft, heat and electrical conductors, lustrous, low density, very reactive
what are the names of all 6 groups?
boron, carbon, nitrogen, chalcogens, halogens, and noble gases.
Who was Mendeleev and what did he do?
Created the periodic table and left holes for other elements not yet identified
Which element is the only transition metal that is a liquid at room temperature?
Mercury
What is the trend for ionic radius?
increases left and down
what is group 2 called and what are some characteristics?
alkaline-earth metals and they dissolve in water, solid at room temp., dense, hard, higher melting points than group 1, malleable, reactivity increases as you go down
What are characteristics of the boron group?
metallike as atom,ic # increases, malleable, ductile, corrodes in presence of oxygen
What unidentified element did Mendeleev leave a space for?
Gallium
what do elements in the same group tell you?
have the same # of valence electrons
what is the trend for ionization energy?
increases right and up
Are all elements in group 1 metals?
no, H
Why is the carbon group called the carbon group?
Carbon is the basis of life
What is the difference between periodic law and modern periodic law?
properties of elements vary periodically with their atomic masses vs. with their atomic numbers
what is the chronological order of the 4 atomic models?
dalton, thomson, Rutherford, bohr
what is the trend for electron affinity?
increases down and right
what are group 3-12 transition metals characteristics?
high density, 1-2 valence electrons, hard, tough, lustrous, GREAT conductors, ductile, malleable, most pure solids
How reactive are the chalcogen and halogen group elements ands why?
extremely because they only need 2 or 1 more electrons
Periodicity exists when...
when some measurable property regularly repeats in a sequential list or time sequence
What are the 4 divisions that distinguish the elements?
metals, nonmetals, metalloids, and lanthoids & actinoid
what is the trend for electronegativity?
increases right and up
what are the inner transition metals called and what are their characteristics?
lanthanoid and actinoid.
lanthanoid - weakly attracted to magnetic fields, most occur naturally, uniform so difficult to purify
actinoid - first 5 found in nature and all others only in nuclear reactions, dangerous, radioactive
properties of the noble gases?
unreactive, colorless, orderless, tasteless, low boiling and low freezing points