First Exam Flashcards
What is the definition of measurement?
A number with an attached unit found using an instrument
What is a measurement based on?
Personal judgment and instrument precision
What is a non-zero digit?
Any digit that isn’t a zero
Always significant
What is a zero “sandwich”?
Zeros that are between other numbers
Always significant
What is a leading zero?
Zeros that come before a number
Never significant
What is a trailing zero?
Zeros that come at the end of the number (depends on decimals)
Decimal - 1.60 - significant
No decimal - 5000 - not significant
How many sig figs: 354.89
5
How many sig figs: 102.202
6
How many sig figs: 3500
2
How many sig figs: 0.04560
4
Round the number to 3 sig figs: 0.009794012
0.00979
Round the number to 3 sig figs: 234.56
235
Convert the following into scientific notation: 4560
4.56 x 10^3
What scientist is credited with creating the first periodic table?
Dmitri Mendeleev
What are the horizontal rows of the periodic table called?
Periods
What are the vertical columns of the periodic table called?
Groups
What specific family name is given to the elements in Group IA
Alkali metals
What specific family name is given to the elements in Group IIA
Alkaline earth metals
What specific family name is given to the elements in Groups IIIB to IIB
Transition metals
What specific family name is given to the elements in the two rows of elements at the bottom of the periodic table?
Inner transition metals
What specific family name is given to the elements in Group VIIA
Halogens
What specific family name is given to the elements in Group VIIIA
Noble gases
Where are the naturally occurring elements located on the periodic table?
Elements 1-92, except for #43 & 61
What is another name for the manmade elements?
Synthetic
What are the only two synthetic elements between 1 and 92?
Technetium and Promethium
How can you tell if an element is radioactive?
The element has parentheses around their atomic mass
What is the only nonmetal to the left of the zig-zag line?
Hydrogen
What is the term for elements that exist in pairs?
Diatomic elements
Name the diatomic elements
Hydrogen, Oxygen, Nitrogen, Fluorine, Chlorine, Bromine, Iodine
Where are the metals found on the periodic table?
To the left of the zig-zag line
List four general properties of metals
Good conductors, malleable, ductile, high melting points
Where are the nonmetals found on the periodic table?
Right of the zig-zag line (except for Hydrogen)
List four general properties of nonmetals found on the periodic table
Dull, good insulators, usually brittle, lower melting points
What are the elements that have some properties of metals and some properties of nonmetals called?
Metalloids
Where are the metalloids located on the periodic table?
They touch the zig-zag line (except for Al)
Name the metalloids
Boron, Silicon, Arsenic, Tellurium, Astatine, Germanium, Antimony
Which particles compose the nucleus?
Protons and neutrons
Where are the electrons located in an atom?
Outside the nucleus
Which subatomic particle is equal to the atomic number?
Protons
Which subatomic particle determines isotopes?
Neutrons
Which subatomic particles are the same size?
Neutrons and protons
Which subatomic particle has a negative charge?
Electron
What is the mass number equal to?
of protons and # of electrons
Define an isotope:
Atoms of the SAME ELEMENT that have different MASS NUMBERS
What is an ion?
An atom with an electrical charge
What is the atomic mass of an element?
The “weighted average” of the different isotopes
Where is the mass number located on the periodic table?
Not found on the table
What are the units for atomic mass?
amu (atomic mass units)
