Chemistry Mock Regents Review 24-25

Which proposal in the development of the modern model of the atom was made before the others?

• Atoms are hard, indivisible spheres of different sizes.

• Atoms are mostly empty space with a small dense nucleus.

• Atoms have electrons that have wavelike properties.

• Atoms have an internal structure that contains negative particles.

According to the wave-mechanical model, in the ground state, the 10 electrons of a neon atom would be located

• in the nucleus

• in orbitals

• in the first shell

• in the valence shell

Which statement describes two different isotopes of carbon?

• The isotopes contain the same number of neutrons and have the same atomic number.

• The isotopes contain the same number of neutrons but have a different atomic number.

• The isotopes contain a different number of neutrons but have the same atomic number.

• The isotopes contain a different number of neutrons and have a different atomic number.

An element that is a very reactive metal could have an atomic number of

• 9

• 2

• 19

• 79

Tags

NGSS.HS-PS1-1

Which element is listed with the number of protons in each of its atoms?

• nitrogen, 14

• silicon, 14

• oxygen, 16

• phosphorus, 16

What is the overall charge on the nucleus of a fluorine atom?

• -1

• -9

• +9

• +19

As the elements with atomic numbers 11 through 17 are considered in order of increasing atomic number, the classification of the elements changes from

• metal to metalloid to nonmetal

• metal to nonmetal to metalloid

• nonmetal to metalloid to metal

• nonmetal to metal to metalloid

At STP, which property can be used to differentiate one-mole samples of Cl2(g) and Kr(g)?

• phase

• pressure

• chemical reactivity

• temperature

Two gaseous forms of oxygen are diatomic oxygen, O2, and ozone, O3. These two forms of oxygen have

• the same molecular structure and the same properties

• the same molecular structure and different properties

• different molecular structures and the same properties

• different molecular structures and different properties

A compound consists of two or more different elements that are

• physically mixed in a fixed proportion

• physically mixed in a proportion that can vary

• chemically combined in a fixed proportion

• chemically combined in a proportion that can vary