Regents Review #1

The mass of a proton is approximately equal to the mass of

• an alpha particle
• a beta particle
• a positron
• a neutron

An orbital of an atom is defined as the most probable location of

• an electron
• a neutron
• a positron
• a proton

What must occur when an electron in an atom returns from a higher energy state to a lower energy state?

• A specific amount of energy is released.
• A random amount of energy is released.
• The atom undergoes transmutation.
• The atom spontaneously decays.

Which element is a liquid at 305 K and 1.0 atmosphere?

• magnesium
• fluorine
• gallium
• iodine

Which list of elements consists of a metal, a metalloid, and a nonmetal?

• Li, Na, Rb
• Cr, Mo, W
• Sn, Si, C
• O, S, Te

At STP, which physical property of aluminum always remains the same from sample to sample?

• mass
• density
• length
• volume

Which statement describes a chemical property of silicon?

• Silicon has a blue-gray color
• Silicon is a brittle solid at 20. degrees C
• Silicon melts at 1414 degrees C.
• Silicon reacts with fluorine.

Which diagram represents a mixture of two different molecular forms of the same element?

• 1
• 2
• 3
• 4

Which quantities must be conserved in all chemical reactions?

• mass, charge, density
• mass, charge, energy
• charge, volume, density
• charge, volume, energy

Which phrase describes the distribution of charge and the polarity of a CH₄ molecule?

• symmetrical and polar
• symmetrical and nonpolar
• asymmetrical and polar
• asymmetrical and nonpolar