science

Chlorine has an average atomic mass of 35.45 amu. The two naturally occurring isotopes of chlorine are chlorine-35 and chlorine-37. Do most chlorine atoms contain 18 neutrons or 20 neutrons? Why?

18

the number of neutrons in potassium-40.

21

In which of the following states is nitrogen found at room temperature? A) gas C) metal B) plastic D) liquid

A

The periodic table is organized into columns called ________. A. groups C. periods B. categories D. rows

A

is the weighted-average mass of all the known isotopes for an element.

Atomic mass

Determine the mass number and the atomic number of a chlorine atom that has 17 protons and 18 neutrons.

Atomic number 17 Mass number 35

The atomic number of Re is 75. The atomic mass of one of its isotopes is 186. How many neutrons are in an atom of this isotope? A) 75 C) 186 B) 111 D) 261

B

What is the name for all the elements in region B on the periodic table above? A. metals B. metalloids C. nonmetals D. transition metals

B

What is the term for a repeating pattern? A) isotopic C) periodic B) metallic D) transition

B

Which element has properties that are simi- lar to neon? A) aluminum B) argon C) arsenic D) silver

B

Which term describes boron? A) metal C) noble gas B) metalloid D) nonmetal

B

The element nickel has five naturally occur- ring isotopes. Which of the following describes the relationship of these isotopes? A. same mass, same atomic number B. same mass, different atomic number C. different mass, same atomic number D. different mass, different atomic number

C

The table above shows electron arrangements of some elements. Which element in the table has a complete outermost energy level? A. carbon B. oxygen C. neon D. sodium

C

What particle identifies each particular element? A. electrons C. protons B. photons D. quarks

C

Which of the following is NOT found in the nucleus of an atom? A) proton C) electron B) neutron D) quark

C

Identify the chemical symbols for the elements carbon, aluminum, hydrogen, oxygen, and sodium.

Carbon- C Aluminum- Al Hydrogen- H Oxygen- O

Which of the elements below is a shiny element that conducts heat and electricity? A) chlorine C) hydrogen B) sulfur D) magnesium

D

Use the periodic table to find the name, atom- ic number, atomic mass, and the number of outermost electrons for each of the following elements: N, P, As, and Sb.

Don't worry about outermost electrons Symbol Element atomic number mass number N Nitrogen 7 14.007 P phosphorus 15 30.974 As arsenic 33 74.922 Sb antimony 51 121.76

the symbol, the group number, and the period of each of the following elements: nitrogen, sodium, iodine, and mercury.

ELEMENT SYMBOL GROUP # PERIOD Nitrogen N 15 2 Sodium NA 1 3 Iodine I 17 5 Mercury Hg 12 6

In the current model of the atom, the elec- trons are located in the _______.

Electron cloud

Two elements with the same number of pro- tons but a different number of neutrons are called _______.

Isotope

The _______ is the sum of the number of protons and neutrons in an atom.

Mass number

The positively charged center of an atom is called the _______.

Nucleus

Identify the names, charges, and locations of three types of subatomic particles that make up an atom.

Protons- positive charge and found in the nucleus Electrons- negative charge found orbiting the nucleus Neutrons- neutral found in the nucleus

The particles that make up protons and neutrons are called _______.

Quarks

Classify each of the following elements as a metal, a nonmetal, or a metalloid and give the full name of each element: K, Si, and S.

SYMBOL ELEMENT TYPE OF ELEMENT K Potassium metal Si silicon metalloid S sulfur nonmetal

Most of the elements to the left of the stair- step line in the periodic table exist as _________ at room temperature. A) gases C) plasmas B) liquids D) solids

d

A(n) _______ is a horizontal row in the periodic table.

period