Chapter 4: Atoms and Elements

Question 1

List the four key concepts of Dalton’s atomic theory

Answer 1

1. Elements are made of tiny particles called atoms. 2. Atoms of one element are different from atoms of other elements. 3. Atoms join in whole number ratios to form compounds.4. Atoms are unchanged in a chemical reaction

Question 2

Describe the generalized results of the gold foil experiments.

Answer 2

Results from the experiment: some particles veered off in angles after going thru the foil. Some particles went backward, struck solid and bounced back. Most went straight thru. Most of an atom is empty space.

Question 3

Describe Rutherford’s nuclear model of the atom.

Answer 3

Rutherford believed that there was a dense charge in the center of the atom, which is the nucleus. Most of an atom is empty space with electrons moving around in the nucleus, which is a negative charge

Question 4

The three important subatomic particles of an atom are the electron (discovered 1897), the proton (discovered 1919), and the neutron (discovered 1932). Remember the basic properties (relative charge, relative mass, and location in the atom) of these three subatomic particles.

Answer 4

Protons are in the nucleus and have positive charge. Neutrons have neutral charge and are in the nucleus. Electrons surround the nucleus and have a negative charge.

Question 5

Define atomic number.

Answer 5

Atomic number is the number of protons in an atom or element, determine the identity of the element

Question 6

Define (atomic) mass number.

Answer 6

The number of protons and neutrons in an atom

Question 7

Define an isotope

Answer 7

Atoms of the same element but different number of neutrons and atomic mass.

Question 8

Correctly write the nuclear symbol of any isotope of any element.

Answer 8

the number of neutrons and protons in a superscript to the left of the element symbol

Question 9

Decode an isotope symbol (also called atomic notation) to determine the number of all three subatomic particles present in an atom.

Answer 9

There are equal number of protons and electrons in an element. The right subscript is the number of protons, and the left superscript is the isotope number (electrons + neutrons)

Question 10

The number of which subatomic particle determines the identity of an element?

Answer 10

Protons determine the identity of an element

Question 11

Describe how the periodic table is organized

Answer 11

Periodic table is arranged by rows and columns with similar properties, column is a family or group, rows are periods

Question 12

Remember the family names for these groups: 1A (1),2A (2), 7A (17), 8A (18).

Answer 12

Alkali metal is column 1, IA: Li, Sodium, Potassium, Rubidium, Cesium. Alkali earth metals, column 2, IIA: Beryllium, magnesium, Calcium, Strontium, Barium. Halogen, column 17, VIIA: Florine, chlorine, Bromine, iodine
Nobel gases, column 18, VIIIA: Helium, neon, argon, krypton, xenon, radon

Question 13

Remember the location of the representative (main group) elements.

Answer 13

Left two columns and right five columns

Question 14

Remember the location of transition elements (B groups).

Answer 14

The middle columns of elements

Question 15

Remember the location of inner transition elements.

Answer 15

Inner transitional elements are the bottom two rows of elements

Question 16

Remember the general names for each inner transition element series.

Answer 16

Lanthanoids and Actinoids are the names of the inner transitional element series.

Question 17

Remember whether an element is classified as a metal, nonmetal, or metalloid based on its position in the periodic table

Answer 17

Metal elements are anything to the right of Al, Ge, Antimony, Polonium. Metalloids are all elements of Boron (including, Si, As and Tellurium). Non-metals are to the right of Carbon, Phosphorus, Selenium, Iodine and Radon.

Question 18

List the common physical properties of metals.

Answer 18

Metals are shiny, conduct heat and electricity are malleable, ductile and have generally high melting point and density.

Question 19

Define a metalloid (semi-metal) based on their similarities to metals and nonmetals.

Answer 19

Metalloids can have properties of metals and nonmetals.

Question 20

Define the meaning of a diatomic element. List the seven diatomic elements and their symbols.

Answer 20

Diatomic elements have two atoms to an element. The seven diatomic elements are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine and Iodine. (Have No Fear Of Ice Cold Beer)

Question 21

Define valence electrons.

Answer 21

Valence electrons are the outermost electrons to any atoms

Question 22

The arrangement of which subatomic particle determines the chemical properties of an element?

Answer 22

The arrangement of ELECTRONS determines the chemical properties of an element

Question 23

Describe how an atom becomes an ion.

Answer 23

Ions are charged atoms (when atoms gain or lose electrons).

Question 24

Explain the difference between a positively charged ion and a negatively charged ion.

Answer 24

Positively charged ions has lost one or more electrons so more protons than electron. Negatively charged ions have lost one or more electrons so more electrons than protons.

Question 25

Define a cation.

Answer 25

A positively charged ion

Question 26

Define an anion.

Answer 26

A negatively charged ion.