10th - 12th grade
Which statement describes the earliest model of the atom?
In all atoms of bismuth, the number of electrons must equal the
Which symbol represents a particle that has a mass approximately equal to the mass of a neutron?
An orbital is a region in an atom where there is a high probability of ﬁnding
Which electron shell in an atom of calcium in the ground state has an electron with the greatest amount of energy?
As the elements in Period 2 are considered in order from lithium to ﬂuorine, there is an increase in the
Which element is classiﬁed as a metalloid?
Strontium and barium have similar chemical properties because atoms of these elements have the same number of
Which element has metallic bonds at room temperature?
What is the number of electrons shared between the atoms in a molecule of nitrogen, N2?
Given the equation representing a reaction: H + H → H2
What occurs during this reaction?
An atom of which element has the strongest attraction for electrons in a chemical bond?
Which statement describes a mixture of sand and water at room temperature?
According to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas?
Which sample of matter has the greatest distance between molecules at STP?
Which electron conﬁguration represents the electrons in an atom of sulfur in an excited state?
Which notations represent atoms that have the same number of protons but a different number of neutrons?
Which compound has covalent bonds?
At which temperature and pressure will a sample of neon gas behave most like an ideal gas?
The volumes of four samples of gaseous compounds at 298 K and 101.3 kPa are shown in the table below.
Sample Compounds Volume (L)
1 NH3(g) 44.0
2 CO2(g) 33.0
3 HF(g) 44.0
4 CH4(g) 22.0
Which two samples contain the same number of molecules?
Graphite and diamond are two forms of solid carbon at STP. These forms have
In the ground state, an atom of which element has seven valence electrons?
Which information is sufficient to differentiate a sample of sodium from a sample of silver?
Which statement explains why NaBr is classified as a compound?
Which substance can not be broken down by a chemical change?
The degree of polarity of a covalent bond between two atoms is determined by calculating the difference in their
At STP, which property of a molecular substance is determined by the arrangement of its molecules?
Which ion in the ground state has the same electron configuration as an atom of neon in the ground state?
The molar masses and boiling points at standard pressure for four compounds are given in the table below.
Which compound has the strongest intermolecular forces?
Which particle model diagram represents xenon at STP?