ch. 17 Flashcards
how did mendeleev arrange his periodic table?
by increasing the mass
In a periodic table a set of properties repeats from ____ to ____
row to row
what is eka-aluminum? how did it get its name?
Gallium, it had similar properties to alluminum
the atomic mass of a unit is based off what element/isotope?
carbon-12
what is atomic mass?
Z=, sum of protons and nucleus
what are alkali metals, what are earth metals ?
1A, highly reactive. 2A, 2nd most reactive
grp 7A contains the ____, are they reactive or unreactive?
Halogens, highly reactive
atoms of the most reactive elements tend to have how many valence electrons?
7 or/to 1
what gives an element the tendency to react?
number of valence electrons.
elements are more reactive from ___ to ___ in a column on the periodic table
top, bottom
to keep reacting, elements are stored in ____
Argon
what element is found in nature only in compounds
Sodium
what element is found in your body that contains most compounds
carbon
elements in the same ____ share similar properties
group, family, column
how was mandeleevs periodic table useful?
explain and predict
