chemistry (ch 2)

Question 1

element

Answer 1

a quantity of matter composed of atoms of the same type.

Question 2

chemical elements

Answer 2

a limited number of building blocks that make up all forms of matter (living and nonliving)

Question 3

chemical symbol

Answer 3

each element is designated by 1 or 2 letters of the element’s name in English, Latin, or another language

Question 4

major elements for the human body

Answer 4

oxygen, carbon, hydrogen, and nitrogen

Question 5

lesser elements for the human body

Answer 5

calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium and iron

Question 6

atoms

Answer 6

the smallest units of matter that have the properties and characteristics of the element

Question 7

subatomic particles

Answer 7

they compose individual atoms: protons, neutrons and electrons

Question 8

nucleus

Answer 8

the dense central core of an atom

Question 9

protons

Answer 9

large, positively-charged particles; the number of protons controls the type of element

Question 10

neutrons

Answer 10

neutrons have no charge; they do add mass and are responsible for isotopes

Question 11

electrons

Answer 11

electrons are very small and light; located in a “cloud” of probability

Question 12

atomic number

Answer 12

the number of protons in the nucleus of an atom

Question 13

mass number

Answer 13

the sum of the protons and neutrons in an atom

Question 14

Isotopes

Answer 14

the atoms of an element that have different numbers of neutrons and therefore different mass numbers

Question 15

radioactive isotopes

Answer 15

isotopes that are unstable; their nuclei decay (spontaneously change) into a stable configuration