Practice Chemistry Regents (326)

Which phrase describes the nucleus of any atom?

• has an overall positive charge

• has an overall negative charge

• contains negative electrons

• contains positive electrons

Tags

NGSS.HS-PS1-8

Which two particles each have a mass of approximately one atomic mass unit?

• an electron and a proton

• an electron and a positron

• a neutron and a proton

• a neutron and a positron

The wave-mechanical model of the atom describes the location of electrons as

• loosely packed in the nucleus of an atom

• as densely packed in the nucleus of an atom

• in circular paths around the nucleus

• in orbitals outside the nucleus

When a ground state electron in an atom moves to an excited state, the electron

• absorbs energy as it moves to a higher energy state

• absorbs energy as it moves to a lower energy state

• releases energy as it moves to a higher energy state

• releases energy as it moves to a lower energy state

Which statement describes a chemical property of iron?

• Iron is malleable.

• Iron conducts electricity.

• Iron reacts with nitric acid.

• Iron has a high melting point.

Diamond and graphite are two forms of solid carbon. These two forms of carbon have

• different crystal structures and different properties

• different crystal structures and the same properties

• the same crystal structure and different properties

• the same crystal structure and the same properties

Tags

NGSS.HS-PS1-3

Which substance can be broken down by a chemical change?

• cobalt

• ethane

• krypton

• manganese

Based on Table I, which equation represents conservation of mass and energy?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-7

At STP, which property can be used to differentiate a 10-gram sample of NaCl(s) from a 10-gram sample of NaNO₃(s)?

• mass of the sample

• temperature of the sample

• solubility in water

• phase at STP

What is the number of electrons shared between the two atoms in an O₂ molecule?

• 6

• 2

• 3

• 4