Chapter 4

Question 1

Atom

Answer 1

smallest particle of an element that retains the properties of the element

Question 2

Electrons

Answer 2

Negatively charged particles that are a part of all forms and makeup atoms

Question 3

Nucleus

Answer 3

tiny dense region centrally located within an atom which contains the protons and virtually all of its mass.

Question 4

Protons

Answer 4

subatomic particle carrying an equal (but opposite) charge to that of an electron (charge of +1)

Question 5

Neutrons

Answer 5

Mass nearly equal to a proton, but it carries no electrical charge.

Question 6

Element’s Atomic Number

Answer 6

Number of protons in an atom; this number determines an element’s place on the periodic table (ie Hydrogen (H) has 1 proton, so it is the 1st element in the periodic table)
Furthermore, all atoms are neutral, so the number of protons and electrons must be equal.

Question 7

Isotopes

Answer 7

even though all atoms of a particular element have the same of protons and electrons, the number of neutrons in the nuclei may differ; Atoms that have the same number of protons but different numbers of neutrons are called Isotopes

Question 8

Mass Number

Answer 8

To make it easy to identify isotopes of an element, chemists add a number after the element’s name known as the mass number, which is the sum of the number of protons and neutrons in the nucleus.

Question 9

Atomic Mass Unit (AMU)

Answer 9

One atomic mass unit is defined as 1/12 the mass of a carbon-12 atom, although the mass of one AMU is very nearly the equal to the mass of a single proton or neutron

Question 10

How To Calculate Atomic Mass!

This one is important, if you need to read more about it go to page 103 in the chem textbook

Answer 10

atomic mass is the average mass of the isotopes of an element
(ie the atomic mass of chlorine is 35.453 amu, it exists as 75.770% chlorine-35 (34.969 amu) and 25.230% chlorine-35 (36.966 amu) atoms, so
1) multiply the percentage of occurrence of each isotope by that isotope’s amu to find the mass contribution
(35.453)(.75.770)=26.496 amu ; (34.969)(25.230)= 8.957 amu
2) Then, add the two products and you’ve found the average atomic mass!
26.496+8.957= 35.453 amu
good job! :)

Question 11

Nuclear Reactions

Answer 11

A reaction in which an atom’s nucleus in changed in order for an atom of one element to change into the atom of another element

Question 12

Radioactivity

Answer 12

when a substance spontaneously emits radiation

Question 13

Radiation

Answer 13

Rays and particles emitted by by radioactive material

Question 14

Alpha Radiation (p106)

Answer 14

radiation that’s made up of alpha particles, each particle containing two protons and two neutrons, thus having a charge of (+2)
opposite electrical charges attract, so alpha particles are attracted to negatively charged particles

Question 15

Beta Radiation (p107)

Answer 15

fast moving electrons called beta particles, each having a charge of (-1)
these particles are attracted to positive particles

Question 16

Gamma Rays (p107)

Answer 16

high-energy radiation that possess no mass are denoted by the symbol 0/0 y
gamma rays have no charge so they’re not attracted to anything, but they do account for most of the energy lost during the radioactive decay process

Question 17

Nuclear Equation (p106)

Answer 17

look in the textbook babe i can’t type this stuff out 0_0