chapter 16
the smallest piece of an element that still retains the properties of the element is a(n) ____
atom
the number of protons in an atom is the___
atomic number
the___ of an element is the weighted-average mass of the mixture of its isotopes
average atomic mass
metalloids
boron and silicon, for example
a particle that moves around the nucleus is a(n) ___
electron
the area where electrons are most likely to form
electron cloud
a(n) _____ uses the symbol of the element and dots to represent the electrons in the outer energy level
electron dot diagram
each inner energy level of an atom has a maximum number of___it can hold
electrons
elements that have properties halfway between those of metals and nonmetals, are classified as___
metalloids
all___except mercury are solids at room temperature
metals
which category of elements have the property of being malleable and ductile?
metals
a chemical symbol represents the___of an element
name
electrons have ___charge
negative
electrons have___charge
negative
electron
negative charge
the main difference between protons and electrons is that protons have___charge and electrons have ___ charge
positive, negative
the mass number of an atom is the sum of___and neutrons
protons
the smallest part in an atom
quark
particles of matter that make up protons and neutrons are___
quarks
protons are made of___
quarks
elements in groups 3 through 12 are called___
transition elements
according to present atomic theory, the location of an electron in an atom cannot be pinpointed exactly
true
according to the present atomic theory, the location of an electron in an atom is best represented by a probability cloud
true
one proton and one electron are added to each element as you go across the periodic table
true
so far, scientists have confirmed the existence of six different quarks
true
the atomic number of an element is determined by its number of protons
true
the sixth quark is also known as the top quark
true
the sum of the number of protons and neutrons in an atom is the mass number
true
oxygen and sulfur have similar chemical properties and___
valence electrons\atomic structure
which metalloid is in the fourth period and the same group as carbon?
Germanium
a certain atom has 26 protons, 26 electrons, and 30 neutrons. its mass number is ___
56
a(n) ___ is matter that is composed of one type of atom
element
where electrons are located in every atom
energy levels
the maximum number of electrons in the second energy level of an atom is 4
false, 8
the symbol for chlorine is C
false, Cl
the weighted average of the mass numbers of all the isotopes that occur in nature for a particular element is the average atomic number
false, atomic mass
as you move from left to right in a row of the periodic table, metallic properties increase
false, decrease
moving from left to right in a row of the periodic table, metallic properties increase
false, decrease
the region around the nucleus occupied by the electrons is called the negative zone
false, electron cloud
for an atom to be neutral, the number of protons must be equal to the number of neutrons
false, electrons
elements arranged in vertical columns in the periodic table are called periods
false, groups
the atomic masses of the elements are not whole value numbers because of the existence of quarks
false, isotopes
the atomic number of an atom is the sum of the number of protons in the number of neutrons in the nucleus
false, mass number
the central core of an atom is called the hub
false, nucleus
protons are made of neutrons
false, quarks
the number of electrons in an elements outermost energy level determines the___of the element
group
the vertical columns in the periodic table are called___
groups
metals
iron, zinc, and copper, for example
atoms of the same element with different numbers of neutrons are called___
isotopes
what carbon-12 and carbon-14 are
isotopes
neutrons have___charge
neutral/no
chlorine-35 and chlorine-37 have a different number of___
neutrons
the mass number minus the atomic number equals the number of___
neutrons
neutron
no charge
Rutherford's contribution to atomic models was the discovery of the___
nucleus
most of the mass of an atom is found in its___
nucleus
where most of the mass of an atom is located
nucleus
the periodic table is organized by atomic___because it always increases left to right
number
dot diagrams are used to represent___
outer electrons
nonmetals
oxygen, bromine, and carbon, for example
horizontal rows of the periodic table are called___
periods
the horizontal rows in the periodic table are called___
periods
protons have___charge
positive
proton
positive charge