3.1 What are the elements?

Question 1

Matter

Answer 1

anything that has a volume & mass> solid, liquid, or gas

Question 2

Element

Answer 2

a substance that cannot be broken down into simpler substances by physical or chemical means (identified by a chemical symbol)

Question 3

How many elements occur on Earth & in the stars?

Answer 3

92

Question 4

Atom

Answer 4

the smallest particle of an element that has all of the characteristics of that element

Question 5

Nucleus

Answer 5

center of an atom that is made up of protons & neutrons

Question 6

Proton (p+)

Answer 6

a tiny particle that has a mass & a positive electrical charge

Question 7

Neutron(n^0)

Answer 7

a particle with abut the same mass as a proton, electrically neutral> no electrical charge

Question 8

What do all atomic nuclei have?

Answer 8

a positive charge> protons with a positive electrical charge & neutrons with no electrical charges

Question 9

Atomic Number

Answer 9

number of protons in an atom’s nucleus

Question 10

Mass Number

Answer 10

combined number of protons & neutrons

Question 11

Electron(e-)

Answer 11

surround the nucleus of the atom> little mass, negative electrical charge

Question 12

Energy Level

Answer 12

represents the area in an atom where an electron s most likely to be found

Question 13

Valence Electrons

Answer 13

outermost electrons that determine the chemical behavior of elements

Question 14

Isotopes

Answer 14

atoms of the same element that have different mass numbers & the same chemical properties

Question 15

Atomic Mass

Answer 15

average of the mass numbers of the isotopes of an element

Question 16

Radioactivity

Answer 16

spontaneous process through which unstable nuclei emit radiation