Science chapter 3

Ace your homework & exams now with Quizwiz!

atomic mass unit (amu)

1/12 the mass of a carbon-12 atom

subatomic

Dalton theorized that atoms are indivisible, but the discovery of _____ particles change this theory

small whole-number

Dalton's atomic theory included the idea that the atoms of different elements can chemically combine in _____ ratios

negative, protons, neutrons

scientists now know that atoms are made of elections, which have a _____ charge; _____, which have a positive charge; and _____, which are neutral

cathode ray

stream of electrons produced at the negative electrode of a tube containing gas at low pressure

atomic mass

the _____ of an element is the weighted average of the masses of the isotopes of that element

always

the atomic number of an atom is the total number of protons in an atom of that element

always

the charge on all protons is the same

period

a horizontal row of the periodic table

proton

a neutron has no charge, but its mass is almost the same as that of a _____

group

a vertical column of elements in the periodic table

never

according to Dalton's atomic theory, atoms are composed of protons, electrons & neutrons

chemical reaction

an atom is the smallest particles of an element that retains its identity in a _____

sometimes

an atom of nitrogen has 7 protons & 7 neutrons

sometimes

atoms combined in one-to-one rations to form compounds

different

atoms of any one element are _____ from those of any other element

compounds

atoms of different elements can form _____ by combining in whole-number ratios

sometimes

atoms of elements are electrically neutral

always

atoms of one element are different from atoms of other elements

never

atoms of one element change into atoms of another element during chemical reactions

neutrons

atoms of the same element are identical in most respects, but they can differ in the number of _____ in the nucleus

isotopes

atoms that have the same number of protons but different mass numbers are called _____

electrons

because atoms are electrically neutral, the number of protons & _____ in an atom are equal

separated, joined, rearranged

chemical reactions occurs when atoms are _____, _____, or _____

1

each of the three known isotopes of hydrogen has _____ proton(s) in the nucleus

atoms

elements are composed of tiny particles called _____

mass number

equals the number of neutrons plus the number of protons in an atom

electrons

in contrast, the negatively charged _____ occupy most of the volume of the atom

mass

isotopes of an element have different numbers of neutrons. they also have different _____ numbers

1

it has a mass number of _____ and is called hydrogen-1

Rutherford

it was _____ who discovered the nucleus of the atom

atomic number

number of protons in the nucleus of an atom of an element

always

relative atomic masses are expressed in amus

never

the atomic number of an element is the sum of the protons & electrons in an atom of that element

atomic numbers

the elements in the period table are listed in order of increasing _____

nucleus

the latter two particles are found in the _____ of the atom

30

the mass number of an element with 14 electrons & 16 neutrons is _____

never

the mass of an election is equal to the mass of a neutron

0

the most common hydrogen isotope has _____ neutrons

positive

the nucleus, which has a _____ charge, occupies a very small volume of the atom

proton

the number of _____ in the nucleus of an atom is the atomic number of that element

always

the number of neutrons in the nucleus can be calculated by subtracting the atomic number from the mass number

atomic

the number of protons in an atom is called its _____ number

protons

the total number of _____ and neutrons in an atom is the mass number

156

the total number of subatomic particle in an atom of silver-109 (atomic number 47) is _____

8

there are 10 neutrons and _____ electrons in an atom of oxygen-18

protons & neutrons

what subatomic particles are found in the nucleus of an atom?

electrons & protons

which subatomic particles are charged?


Related study sets

CH. 9-11 Book Questions FIN-4970

View Set

chapter two: values and attitudes

View Set

Chapter 12: Math Fundamentals on the GRE

View Set

Psych 314 Exam 3 Multiple Choice

View Set

IMC Exam 3 Chapter 10 Sample Questions

View Set

fitness assessment and design quiz 4

View Set

Property and Casualty Texas State Exam

View Set