Chemistry

Question 1

Periodic table was devised by ____ in 1869

Answer 1

Dmitri Mendeleev (1834-1907) a Russian chemist

Question 2

Groups are represented by ____ on the periodic table

Answer 2

Columns

Question 3

Periods are represented by ____ on the periodic table

Answer 3

Rows

Question 4

Chemical reactivity

Answer 4

the ability to form chemical bonds with other atoms

Question 5

the weighted average for an elements’ naturally occurring isotopes on earth

Answer 5

An elements atomic mass is

Question 6

The Bohr model shows the atom as

Answer 6

having a central nucleus containing protons and neutrons, with the electrons in circular shells around the nucleus

Question 7

Electron shells closer to the nucleus have _ energy

Answer 7

lower

Question 8

Groups and periods are arranged on the periodic table in order to show an element’s

Answer 8

physical state at room temperature and its chemical reactivity

Question 9

An early model of the atom was developed by ___ in 1913

Answer 9

Niels Bohr (1885–1962) a Danish scientist

Question 10

Differences in chemical reactivity between elements are based on

Answer 10

the number and spatial distribution of their electrons

Question 11

In order to move between shells, an electron must absorb or release an amount of energy corresponding ____

Answer 11

exactly to the difference in energy between the shells

Question 12

If two atoms have ____, they can react and form a chemical bond, creating a ____

Answer 12

complementary electron patterns, molecule or compound

Question 13

when an excited electron drops back down to a lower-energy shell, it will release energy, often in the form of ___

Answer 13

heat

Question 14

The atomic number shows how many ___ an element has

Answer 14

protons

Question 15

The Bohr model is useful to explain the _____ and _____ of many elements

Answer 15

reactivity , chemical bonding

Question 16

Electron orbitals are

Answer 16

regions of space around the nucleus where electrons spend most of their time

Question 17

s subshells have what kind of shape?

Answer 17

single, spherical orbital

Question 18

p subshells have what kind of shape?

Answer 18

three dumbbell-shaped orbitals at right angles to each other

Question 19

s and p subshells are most important to be familiar with because

Answer 19

most of organic chemistry involves interactions between electrons in those subshells

Question 20

d and f subshells are more complex and have how many orbitals

Answer 20

5 - 7

Question 21

In the Bohr model, electron shell __ corresponds with 1s orbitals

Answer 21

1n

Question 22

the ___ orbital is the closest to the nucleus

Answer 22

1s

Question 23

What orbital gets filled first with electrons?

Answer 23

1s

Question 24

How would you show Hydrogen in electron configuration?

Answer 24

1s^1

Question 25

Each row on the periodic table of elements reperesents

Answer 25

the filling of a different electron shell

Question 26

on the periodic table of elements, a column number gives info about number of ____ and ____

Answer 26

valence electrons and reactivity

Question 27

the valence electrons of elements in a certain column on the periodic table of elements are ____

Answer 27

equal

Question 28

group number is a good predictor of

Answer 28

how reactive an element may be

Question 29

elements that satisfy the octet rule are

Answer 29

less reactive

Question 30

non-reactive elements are called

Answer 30

inert gases or noble gases

Question 31

group 18 on the periodic table of elements are called

Answer 31

inert or noble gases

Question 32

unstable atoms can become more stable by

Answer 32

losing or sharing a valence electron

Question 33

elements that fully lose an electrons become

Answer 33

positively charged ions

Question 34

group 17 elements that have 7 electrons in their outer shell tend to achieve a stable octet by

Answer 34

taking electrons from other atoms

Question 35

when an element takes an electron from other atoms, they become

Answer 35

negatively charged ions

Question 36

If there is an even number of electrons in the outer shell of an atom, those elements tend to achieve a complete valence shell by

Answer 36

forming bonds with multiple other atoms

Question 37

The 2n shell of the Bohr model has what kind of electron orbitals

Answer 37

one spherical s orbital and three dumbbell shaped p orbitals

Question 38

Each orbital in the 2n shell can hold how many electrons?

Answer 38

2

Question 39

Electrons will fill what kind of orbital first?

Answer 39

s

Question 40

Elements in the second row of the periodic table place their electrons in what shells?

Answer 40

2n and 1n

Question 41

Third-row elements on the periodic table place their electrons in what orbitals/shell?

Answer 41

s and 3-p orbitals/3n

Question 42

Why does the d orbital of the 3n shell not begin to fill until the fourth row of the periodic table?

Answer 42

It is considerably higher in energy than the 3s and 3p orbitals

Question 43

Aufbau means ____ in german

Answer 43

building

Question 44

What are the three "blocks" on the periodic table?

Answer 44

s, d, and p

Question 45

Why do electron configuration models go from 2s to 2p instead of 2s to 1p?

Answer 45

The P "dumbbell" shape is not needed for the first shell. By using quantum numbers we see that the first shell only has one orbital and that will defer to the sphere shape and thus it will be 1s

Question 46

If each electron orbital can hold 2 electrons, how is it possible to have 2p^6 for an electron configuration?

Answer 46

The second shell can fit 6 electrons

Question 47

In the following elements, there is 1 electron, not the predicted 2, in the outermost s subshell, the "missing" electron is instead located in the outermost d subshell:

Answer 47

Cu, Cr, Nb, Mo, Ru, Rh, Ag, Pt, Au

Question 48

In Pd (palladium) configuration is

Answer 48

[Kr] 4d¹⁰ (the 5s is empty).

Question 49

All the other exceptions are in the f block. Here are the f-block exceptions:

Answer 49

La, Ce, Gd, Ac, Th, Pa, U, Np, Cm, Lr

Question 50

Z-effective is high on the right side of the periodic table of elements because

Question 50

The d orbital can hold how many electrons?

Answer 50

10

Question 51

How can you tell how many core electrons an element has?

Question 52

How can you tell how many valence electrons an element has?

Answer 52

by group # on periodic table

Question 53

Ionization energy is

Answer 53

the energy required for an atom to lose electrons

Question 54

Electron affinity is

Answer 54

the tendency for an atom to attract electrons

Question 55

Electronegativity is

Answer 55

the tendency for an atom to hog electrons over lending them when atomic bonds are being made

Question 56

True or false : the noble gases don't like to gain or lose an electron

Answer 56

True

Question 57

In a neutral atom # of protons matches # of electrons

Question 58

Can you find the percent chlorine by mass for compounds containing chlorine?

Answer 58

Yes, I need the molar masses of each element in the compound. I then need to divide the molar mass of chlorine by the total molar mass of the compound.

Question 59

In a water molecule, why is there a partial negative charge on the oxygen side and positive on the hydrogen?

Answer 59

Electronegativity of oxygen causes there to be a more negative charge due to its tendency to hog electrons. There is a positive charge around hydrogen as the electrons are being pulled closer to the oxygen side.

Question 60

Photoelectric effect can be used to calculate energy of electrons by

Answer 60

If we know the kinetic energy of the ejected electrons (known as photoelectrons) and the energy of the incident radiation, we can calculate the energy of the electrons in the solid metal