Chem lab midterm
a tentative model or picture that offers an explanation for a scientific law is called a what?
hypothesis
the modern version of the periodic law states that when elements are arranged in order of blank Their properties repeat themselves at regular intervals
increasing atomic number
which statement about ionic compounds is incorrect
ionic compounds are charged, they are not electrically neutral
in which of the following sequences is the metric system prefix listed in order of decreasing size
kilo,centi,nano
a set of procedures used to acquire knowledge and explain phenomena is?
known as the scientific method
the number of neutrons in an atom is equal to what?
mass number and atomic number
an element with the properties and immediate between those of metals and nonmetals is called a
metalloid
which of the following is the metric system unit correctly paired with an abbreviation
microgram-Ug
which of the following units of measure is equivalent to a cubic centimeter?
milliliter
the number 80710, when rounded off to two significant figures would appear as?
81000
which of the following statements concerning the known element is correct
98 of the elements are naturally occurring
which of the following statements concerning electron subshells is correct
electrons in a subshell equal Energies
which of the following pairing of terms is incorrect
Theory-- unvalidated hypothesis
group IA elements are called
alkaline metals
the largest atoms are found where in the periodic table
and the lower left
General periodic trends for atomic radii are
atomic radii tend to decrease from left to right within a period and tend to increase from top to bottom within a group
an isotope of which element is used as the standard for the relative mass scale of atoms
carbon
the condensation of steam is an example of a what?
change of state
adding one proton to the nucleus of an atom does what?
converts it to an atom of a different element
when the scientific method is applied to a problem a set of procedures is followed to acquire knowledge and explain phenomena. The procedural steps associated with the scientific method normally occur in the order--?
experiment, fact, scientific law, hypothesis, theory.
which of the following statements about atoms is correct
free, isolated atoms are virtually never encountered in nature.
groups 7 Alpha elements are called
halogens
in which of the following pairs are physical properties
has metallic luster, and melting point less than 1000 degrees Celsius
that description " three substances present, two phases present" is correct for?
heterogeneous mixtures
the most abundant element in the universe are
hydrogen and helium
which of the following sub-disciplines of science is considered a physical science
physics
the state of matter of a substance is determined by its
temperature
which of these is an intensive property
temperature
which statement is correct about elements
the first letter of any chemical symbol is capitalized
which of the following statements concerning the three major temperature scales is incorrect
the freezing point of water has a lower numerical value on the Kelvin scale then on the Fahrenheit scale
atoms are neutral because?
the number of protons equals the number of electrons
which of the following statements concerning the significance of zeros and recorded measurements is incorrect?
trailing zeros are always significant
the number 12.68×10^2, when expressed in standards scientific notation becomes___?
1.268×10^3
which of these samples has the smallest Mass
1.6×10^-4 Mg
the diameters and masses of atoms are, respectively, on the order of
10^-10m and 10 ^-23g
how many total atoms are contained in the following formula KCr(SO4)2
12
which of the following numbers contains two significant figures
190
how many subshells are presented in the third electron shell
3
what is the correct number of significant figures in the answer for the following sum? 8.650+19.6+44.05+18
3
the number 3009.1 expressed in scientific notation to the correct number of significant figures becomes__?
3.0091×10^3
which of the following numbers are none of the zero in the tickets
3100
what is the maximum number of electrons and the n equals 4 shell
32
how many numbers will be in the coefficient when 0.0090110
5
which of the following is an example of a scientific discipline that involves the study of living organisms
Botany
the sub-discipline of chemistry that studies fundamental laws and concepts of chemistry is
General chemistry
which of the following statements describes a chemical property
Sparks are created when sodium material is added to water
which of the following contains an exact number
a gross of paper contains 144 sheets
the number of known nonmetals is blank the number of known metals
about one-quarter of that
which of the following sources of experimental error would probably be classified as a systematic error
accidental miscalibration calibration of the instrument being used
which of the following statements is correct
both elements and compounds are pure substances
which of the following is not a metallic property
brittle
which of the following is a quantized property of an electron
energy
which of the following is a property of both solids and liquids
definite volume
which statement is false
different mixtures of the same two substances must have the same composition
for an element, the blank blank is the last electron added to the element electron configuration when the configuration is written according to the aufbau principle
distinguishing electron
a condensed electron configuration is defined as an electron configuration that uses the chemical symbol of the nearest blank blank element of lower atomic number?
noble gas
which of the following pairs of subatomic particles have charges of equal magnitude but opposite in sign?
protons and electrons
the four areas in the periodic table which the find the location of the distinguishing electron are referred to as the what?
s area, p area, d area, and f area
the element in group 2 Alpha of the periodic table have electron configurations ending in what?
s to the power 2
