Chemistry regents exam practice questions

which equation represents a single replacement reaction

2Al(s) + 6HCl(aq) ----> 2AlCl3(aq) + 3H2(g)

which equation represents conservation of charge

2I- ----> I2 + 2e-

which element requires the least amount of energy to remove the most loosely held electron from a gaseous atom in the ground state

Na

what occurs during this reaction: H + H ----> H2

a bond is formed and energy is released

which emission causes the atomic number of a nuclide to decrease by 2 and its mass number to decrease by 4

an alpha particle

which statement describes the earliest model of the atom

an atom is an indivisible hard sphere

when comparing voltaic cells to electrolytic cells, oxidation occurs at the

anode in both type of cells

for a chemical system at equilibrium, the concentrations of both the reactants and the products must

be constant

which term represents the fixed proportion of elements in a compound

chemical formula

which statement describes the energy and bonding changes as two atoms of fluorine become a molecule of fluorine

energy is released as a bond is formed

which radioactive emission has the greatest penetrating power, but the least ionizing power

gamma ray

based on table n, uranium-238 and uranium-235 have different

half-lives

which term identifies a type of intermolecular force

hydrogen bonding

the mass of an electron is

less than the mass of a neutron

systems in nature tend to undergo changes toward

lower energy and greater randomness

the element in group 14, period 3, of the periodic table is classified as a

metalloid

what statement describes the reactions in an electrochemical cell

oxidation occurs at the anode, and reduction occurs at the cathode

which symbol represents a particle that has a mass approximately equal to the mass of a neutron

p

which particles are found in the nucleus of an argon atom

protons and neutrons

which terms represent two types of organic reactions

saponification and fermentation

according to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas

the particles are considered to have negligible volume

which statement describes a reaction at equilibrium

the rate of formation of the products must equal the rate of formation of the reactants

which statement describes the particles of an ideal gas, based on kinetic molecular theory

the volume of the gas particles is negligible compared with the total volume of the gas

according to the acid-base theory, a base in an

H+ acceptor

which radioisotope requires long-term storage as a method of disposal, to protect living things from radiation exposure over time

Pu-239