Chapter 5 Flashcards
The standard on which the atomic mass unit is based is the mass of a
carbon-12 atom
At room temperature, none of the metals are
gases
The horizontal rows of elements in the periodic table are called
periods
The elements to the left of the dark, staircase line on the periodic table are
metals
Elements within the same vertical column…
have similar but not identical properties
The elements in a period are…
not alike in properties
Elements that do not combine with other elements
noble gases
The elements that are active. strongly nonmetallic, and react readily with metals to form salts are the
halogens
Elements that are always found free in nature and never found combined in a compound are the
noble gases
Which element is found in nature only in compounds?
sodium
The most abundant element in the Earth’s crust is ____.
Oxygen
The most abundant metal in the Earth’s crust is ____.
Aluminum
Metals that can be drawn into thin wires are described as ____.
Ductile
____ is the most abundant element in the earth’s atmosphere.
Nitrogen
The ____ electrons are those found in the outermost energy level of an atom.
Valence
In the modern periodic table, elements are arranged in order of atomic masses. (T/F)
False, Numbers
Elements can be classified as metals, nonmetals, and metalloids. (T/F)
True
Nonmetals are good conductors of heat and electricity. (T/F)
False, poor
The main element in oil’s composition is calcium. (T/F)
False, carbon
Halogens include fluorine, chlorine, bromine, iodine, and astatine. (T/F)
True
Mendeelev arranged the elements in rows of increasing ____
mass
At the time Mendeleev made his table, there were how many known elements?
63
Means a regular, repeating, pattern
Period
An arrangement of elements in columns, based on a set of properties that repeat from row to row.
Periodic table
Atomic number =
number of protons
Periods are based upon
number of energy levels
across a period from left to right, the elements become less ____ and more _____ in their properties.
metallic, nonmetallic
Metallic means-
active
Vertical columns in the periodic table are called:
groups
Groups are based on:
electrons in the last energy level
similar electronic configurations mean…
similar chemical properties in a group
transition metals are in groups
3 through 12
were among the first elements discovered
transition metals
Nonmetals have
low boiling points
metalloids are located
between metals and nonmetals
valence electrons are located in
the highest occupied energy level
The alkali metals are group
1A (1 valence electron)
extremely reactive, found in nature only in compounds
alkali metals
Why does sodium react with water?
Sodium wants to achieve it’s eighth octet, but gives up one valence electron to water. Said valence electron reacts with the molecules in water, leaving one hydrogen molecule over. The hydrogen molecule then combusts, creating an explosion.
The alkaline earth metals are in group…
2A (2 valence electrons)
The alkaline earth metals are (less, more) metallic than alkali metals
less
The Boron family is in group
3A
Carbon family is group
4A
The nitrogen family is group
5A
Transition metals are in group(s)
3-12
the oxygen family is group
6A
The halogens are group
7A
