chem chapter 6 quiz Flashcards Preview

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Flashcards in chem chapter 6 quiz Deck (32)
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0
Q

all atoms need 8 electrons, except…

A

hydrogen needs 2, boron needs 6, beryllium needs 4

1
Q

what element is usually the central atom in lewis structure

A

least electronegative

2
Q

the number of available electrons is equal to the _____________

A

number of valence electrons of the atom

3
Q

shared electrons=

A

N-A (always even)

4
Q

number of bonds=

A

S/2

5
Q

H is never involved in a multiple bond

___,____ and ___ often form double and triple bonds

A

C, N, O

6
Q

total number of electrons should equal the ______ number

A

A

7
Q

what is the metallic trend

A

increases up to down, right to left

8
Q

what is the atomic radii trend

why

A

increases up to down(valence electron is occupying higher energy level/n value increases making radius larger), increases right to left (number of protons increases (nuclear charge) pulling the electrons in tighter making the radius smaller

9
Q

the differences in electronegativities is the classifier of bonds, what are the ranges for each

A

polar covalent 1.7>or equal to x > or equal to .5
pure covalent x<.5
ionic x>1.7

10
Q

isoelectronic means?

A

same number of electrons

11
Q

what is the atomic radii

A

distance from the center of the nucleus to the “edge” of the electron cloud
usually measured in picometers or angstroms (1x10^-10m)
must be in gas form
center of nucleus to center of nucleus divided by 2

12
Q

what is the atomic radii trend for cations?

anions?

A

cations: increases up to down, right to left
anions: increases up to down, left to right

13
Q

when hydrogen becomes an ion, it is just an ____

A

electron

14
Q

______ do not have ionic radii because they do not form ions

A

noble gases

15
Q

what is shielding effect

A

inner electrons shield valence electrons from positive charge of the nucleus (protons) (concert analogy)

16
Q

what is the ionization energy trend

A

increases down to up, left to right

17
Q

ionization energy is always _____ meaning energy is added to the atom to remove the electron

A

endothermic

18
Q

how are ionization energy and atomic radius related

A

inversely proportional

19
Q

what is ionization energy

A

the energy required to move an electron from an atom is ionization energy

20
Q

the larger the atom is, the (harder/easier) it is for electrons to be removed

A

easier

21
Q

why does ionization energy increase left to right? down to up?

A

because atoms towards the right do not want to gain electrons, they want to lose
because the electrons are held in lower-energy orbitals, closer to the nucleus and therefore are more tightly bound (harder to remove).

22
Q

what is the electron affinity trend

A

increases down to up, left to right

23
Q

what is electron affinity

A

a measure of the energy change when an electron is added to a neutral atom to form a negative ion

24
Q

what is electron affinity opposite of

A

ionization energy

25
Q

why does electron affinity increase down to up, left to right

A

because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons

26
Q

what is the electronegativity trend

A

increases down to up, left to right

27
Q

what is electronegativity

A

holding onto its own electrons and taking other ones

28
Q

why does electronegativity increase down to up and left to right

A

This occurs due to a greater charge on the nucleus, causing the electron bonding pairs to be very attracted to atoms placed further right on the periodic table

29
Q

what is the difference between electron affinity and ionization energy

A

electron affinity is a measure of the energy change when an electron is added while ionization energy is the energy required to remove an electron

30
Q

why does fluorine have a higher ionization energy than iodine?

A

it has less electrons-lesser shielding/greater attraction between the electrons and the nucleus

31
Q

why do elements in the same family generally have similar properties

A

they have the same amount of valence electrons