CHEMISTRY:TOPIC ONE

Question 1

the concept that matter is composed of timy discrete particles is generally attributed to the

Answer 1

greeks

Question 2

the first subatomic particle discovered was the

Answer 2

electron

Question 3

according to the law of the conservation of mass, if the products of a reaction have a mass of 64 g, then the total mass of the reactants

Answer 3

must be equal to 64g

Question 4

the gold foil experiment led scientists to conclude that an atoms

Answer 4

volume is mainly unoccupied

Question 5

the model of the atom that pictured the atom with electrons stuck randomly throughout the mass of the atom was called

Answer 5

plum pudding model

Question 6

after bombarding a gold foil sheet with alpha particles, scientists concluded that atoms mainly consist of

Answer 6

empty space

Question 7

experimental evidence indicated that the nucleus of an atom

Answer 7

contains most of the mass of the atom

Question 8

daltons atomic theory states that

Answer 8

atoms of a given element must be identical

Question 9

modern theory pictures an electron as

Answer 9

both a particle and a wave

Question 10

what are the major differences between the plum pudding and planetary models of the atom

Answer 10

the planetary model contains a nucleus and electrons orbiting

Question 11

why did rutherford conclude that the atom was mostly empty space

Answer 11

most alpha particles went through it

Question 12

what is a major difference between the rutherford and the wave mechanical models of the atom

Answer 12

the electrons are in orbitals

Question 13

the atomic mass of an element is defined as the weighted average mass of that elements

Answer 13

naturally occuring isotopes

Question 14

element x has two isotopes. If 72% of the element has an isotomic mass of 84.9 amu and 28% has an isotopic mass of 87 amu, the average atomic mass of element x is numerically equal to

Answer 14

(0.720)(84.9) + (0.280)(87)

Question 15

a neutral atom with 6 electrons and 8 neutrons is an isotope of

Answer 15

carbon

Question 16

the major portion of an atoms mass consists of

Answer 16

neutrons and protons

Question 17

atoms of 16O, 17O, and 18O have the same number of

Answer 17

protons but a different number of neutrons

Question 18

a neutron has approximately the same mass as

Answer 18

a proton

Question 19

the total number of protons and neutrons in the nuclide 35 over 17 Cl is

Answer 19

35

Question 20

what si the nuclear charge of an atom with a mass of 23 and an atomic number of 11

Answer 20

11+

Question 21

compared to the charge and mass of a proton, an electron has

Answer 21

an opposite charge and a smaller mass

Question 22

when electrons in an excited state fall to lower energy levels, energy is

Answer 22

released

Question 23

the characteristic bright line spectrum of an atom is produced when

Answer 23

electrons move from higher to lower energy levels

Question 24

when the electrons of an excited atom fall back to lower energy levels, the emission of energy produces

Answer 24

spectral lines

Question 25

what particle or particles contribute to the mass number of an atom

Answer 25

protons and neutrons

Question 26

compare the charge and mass of an electron and a neutron

Answer 26

electron is negative with no mass neutron is neutral with 1 amu

Question 27

which atom in the ground state contains one completely filled p orbital

Answer 27

neon

Question 28

what is the total number of electrons in the second principal energy level of a calcium atom in the ground state

Answer 28

8

Question 29

what is the total number of occupied s orbital in an atom of nickel in the ground state

Answer 29

4

Question 30

what is the total number of occupied principal energy levels in a neutral atom of neon in the ground state

Answer 30

2

Question 31

in an atom of lithium in the ground state, what is the total number of orbitals that contain only one electron

Answer 31

1

Question 32

what is the total number of completely filled principal energy levels in an atom of argon in the ground state

Answer 32

3

Question 33

what is the total number of electrons needed to completely fill all the orbitals in an atoms second principal energy level

Answer 33

8

Question 34

what is the total number of sublevels in the fourth principal energy level

Answer 34

4

Question 35

what sublevel contains a total of five orbitals

Answer 35

d

Question 36

what is the maximum number of electrons that can occupy the fourth principal energy level of an atom

Answer 36

32

Question 37

what is the total number of unpaired electtrons in an atom of exygen in the ground state

Answer 37

2

Question 38

what is the total number of completely filled sublevels found in an atom of krypton in the ground state

Answer 38

4

Question 39

Which of the following cannot be decomposed by chemical means 1 sodium 2 ethanol 3 sucrose 4 water

Answer 39

Sodium 

Question 40

A compound differs from an element in that a compound

Answer 40

Can be decomposed by chemical reaction

Question 41

A compound differs from a mixture and a compound always has a

Answer 41

Homogenous composition

Question 42

A pure substance that is composed only of identical atoms is classified as

Answer 42

An element

Question 43

Most elements are

Answer 43

Metals

Question 44

What is a characteristic of all mixtures?

Answer 44

Their compositions may vary

Question 45

Heterogeneous material may be

Answer 45

A mixture

Question 46

Which of these materials is a mixture, water air, methane, or magnesium?

Answer 46

Air

Question 47

Each particle contained in hydrogen gas is made up of two identical, hydrogen atoms chemically joined together. hydrogen gas is 

Answer 47

An element

Question 48

Which of the following materials is a pure substance air water fire or earth

Answer 48

Water

Question 49

What is an identifying characteristic of a mixture

Answer 49

A mixture can be separated by physical means

Question 50

Which substance can be decomposed by chemical change, ammonia, aluminum, magnesium, or manganese?

Answer 50

Ammonia

Question 51

The model of the atom that pictured the atom with electrons traveling in circular orbits, was called the

Answer 51

Planetary model

Question 52

If 14 g of substance X reacts completely with 16 g of substance Y to form the product XY the mass of XY

Answer 52

Will be 30

Question 53

Compared to the entire out of the nucleus of the atom is

Answer 53

Smaller and contains most of the atoms mass

Question 54

In a famous experiment, positively charged particles were aimed at a thin sheet of gold foil, the results of the experiment were that

Answer 54

A few of the particles were repelled showing that the gold has a positive core

Question 55

Neutral atoms must contain equal numbers of

Answer 55

Protons and electrons

Question 56

What is true about a compound but not a mixture

Answer 56

The composition of a compound does not vary

Question 57

Compared with an electron proton has

Answer 57

More mass and an opposite charge

Question 58

The total number of electrons in a neutral atom of any element is always equal to the atoms

Answer 58

Number of protons

Question 59

All isotopes of neutral atoms of sodium have

Answer 59

11 protons and 11 electrons

Question 60

An atom in the excited state contains

Answer 60

More potential energy than an atom in the ground state

Question 61

As an electron moves from the excited state to the ground, state the potential energy of the electron

Answer 61

Decreases

Question 62

What particle has the smallest mass?

Answer 62

Electron

Question 63

An element occurs as a mixture of isotopes. The atomic mass of the element is based upon

Answer 63

Both the masses and the relative abundance of the individual isotopes

Question 64

100 g of a clear liquid is evaporated in a few grams of the white crystals remain the original liquid

Answer 64

Homogenous mixture

Question 65

What does different percentages mean? In a word problem?

Answer 65

That it is heterogeneous

Question 66

Two samples of bronze a uniform material are analyzed and found to contain different percentages of tin. Based on this information bronze is likely a

Answer 66

Heterogeneous mixture

Question 67

Many companies around the world, manufacture, ammonia what does this mean?

Answer 67

No matter where it is manufactured, it will have the same composition

Question 68

What is the charge on a particle that contains nine protons 10 neutrons and nine electrons

Answer 68

It’s neutral

Question 69

An element has two isotopes, 90% of the isotopes have a mass number of 20 amu you while 10% have a mass number of 22 amu you the atomic mass of the element

Answer 69

Is closer to 20amu than to 22amu

Question 70

If the atomic number of a neutral element is 35 and its nucleus contains 40 neutrons, which is the following correct 1 the atom is bromine and it has 35 electrons in 2 the atom is bromine, and it has a mass number of 40 3the atom is zirconium and it has a mass number of 75. 4 The atom is zirconium and has 40 electrons.

Answer 70

The atom is bromine and it has 35 electrons

Question 71

An atom of chlorine 35

Answer 71

17. Protons 18 neutrons and 17 electrons.

Question 72

A moon sample was analyzed in a lab. The carbon in the sample was found to be 97.78% carbon 12 and 2.22% carbon 13 according to these data what is the atomic mass of carbon 

Answer 72

12.0222

Question 73

What model did Ernest Rutherford perform?

Answer 73

Nuclear model