Atomic Theory
Which atomic particles are around the nucleus within an atom?
Electrons
It indicates the number of protons inside an atom
Atomic Number
It is defined as the weighted average mass of all naturally occurring isotopes of an element
Atomic Mass
How are called the vertical columns in the periodic table?
Groups
Most of these elements are shiny solids, as well as good conductors of heat and electricity
Metals
Which atomic particles form the nucleus within an atom?
Protons and Neutrons
It indicates the sum of protons and neutrons inside an atom
Mass Number
These are atoms from the same element with different number of neutrons
Isotopes
How are called the horizontal rows in the periodic table?
Periods
These elements exhibit properties that are thypical both of metals and nonmetals
Metalloids
Who was the scientist that confirmed Democritus atomic model?
John Dalton
If an atom of Chlorine (Cl) has 17 protons and 20 neutrons, what is its mass number?
37
Bromine (Br) has two naturally occurring isotopes: Br-79 (50.69%) and Br-81 (49.31%). What is Bromine atomic mass?
79.98 amu
What's the name of the chemist who first arranged the elements in a periodic table?
Dmitri Mendeleev
What category does Calcium (Ca) belong to? Metal, nonmetal or metalloid?
Metal
Who was the first scientist to discover the existence of the nucleus inside the atom?
Ernest Rutherford
If an atom of Nickel (Ni) has an atomic number of 28 and a mass number of 59, how many neutrons does it have?
31
Silver (Ag) has two naturally occurring isotopes: Ag-107 (51.84%) and Ag-109 (48.16%). What is Silver atomic mass?
107.96 amu
How many periods are there in the periodic table?
7
What category does Arsenic (As) belong to? Metal, nonmetal or metalloid?
Metalloid
Who was the first scientist that stated electrons moved around the nucleus in orbits of fixed sizes and energies?
Niels Bohr
If an atom of Platinum (Pt) has an atomic number of 78 and a mass number of 195, how many neutrons does it have?
117
Strontium (Sr) has four naturally occurring isotopes: Sr-84 (0.56%), Sr-86 (9.86%), Sr-87 (7.00%) and Sr-88 (82.58%). What is Strontium atomic mass?
87.71 amu
How many groups are there in the periodic table?
18
What category does Neon (Ne) belong to? Metal, nonmetal or metalloid?
Nonmetal