Question

Explanation?

Answer 1

Sodium must lose its one valence electron in order to have an octet (in the previous principal shell), while sulfur must gain two electrons to get an octet. Consequently, the compound that forms between sodium and sulfur requires two sodium atoms to every one sulfur atom—the formula is Na2S. The two sodium atoms each lose their one valence electron, while the sulfur atom gains two electrons and gets an octet. The Lewis model predicts that the correct chemical formula is Na2S

Answer 2

@Vocaloid

Answer 3

ON this as well: Calcium needs to lose its two valence electrons (to be left with an octet in its previous principal shell), while chlorine only needs to gain one electron to get an octet. Therefore, you must have two chlorine atoms for each calcium atom. The calcium atom loses its two electrons to form Ca2+, and each chlorine atom gains an electron to form Cl–. In this way, both calcium and chlorine attain octets.

Answer 4

I don't get what they mean by you need "..." for each "..."

Answer 5

"Sodium must lose its one valence electron in order to have an octet (in the previous principal shell), while sulfur must gain two electrons to get an octet. Consequently, the compound that forms between sodium and sulfur requires two sodium atoms to every one sulfur atom—the formula is Na2S."

each sodium atom has to lose 1 VE to get an octet
sulfur needs to gain two electrons to get the octet

so if each sodium is donating 1 electron, sulfur needs 2 sodium atoms in order to get the full octet

Answer 6

same logic w/ calcium and chlorine

Answer 7

OKay but why does sodium need to lose one versus gain 7?

Answer 8

sodium has an extra 1 electron in its valence shell

it could technically gain 7 but that would require a tremendous amount of energy, so it's more convenient to lose 1 instead

Answer 9

so where is the cutoff of whether an element should either like gain 5 or lose just the 3

Answer 10

like how do know its better to lose or gain

Answer 11

do you just look at it and see which would require the least amounto f energy and go with that

Answer 12

metals (left side of ptable) like to lose; nonmetals (right side of ptable) like to gain

Answer 13

Calcium needs to lose its two valence electrons (to be left with an octet in its previous principal shell), while chlorine only needs to gain one electron to get an octet. Therefore, you must have two chlorine atoms for each calcium atom.

Answer 14

Don't get this part:

"Therefore, you must have two chlorine atoms for each calcium atom."


Why would you need two chlorine atoms for each calcium atom?

Answer 15

"ON this as well: Calcium needs to lose its two valence electrons (to be left with an octet in its previous principal shell), while chlorine only needs to gain one electron to get an octet. "

each chlorine atom needs 1 electron
each calcium atom gives away 2 electrons

so for each atom to have a full octet, two chlorine atoms need to donate 1 electron each, so calcium gets 2

Answer 16

if it's confusing to think about the actual atoms, try thinking about the charges instead

each chlorine ion has a -1 charge; each calcium ion has a +2 charge, so to get to 0 you need 2 chlorines and 1 calcium (-1 * 2 +2 = 0)

Answer 17

Yeah it is easier this way

Answer 18

How do you know the charges

Answer 19

ptable

Answer 20

Write the symbol for the metal cation and its charge followed by the symbol for the nonmetal anion and its charge. Determine charges from the element’s group number in the periodic table (refer to Figure 3.12).

Al3+O2–

Answer 21

alright any ideas? if aluminium is +3 and O is -2 how many of each do you need to get 0 charge?

Answer 22

so al is the metal and o is the nonmetal

Answer 23

yes

Answer 24

2 o's for every one al?

Answer 25

IDk its not balancing out :S

Answer 26

no, if you had 2O and 1Al that would be -2(2) + 3 = -1

Answer 27

easy question what's the least common multiple of 2 and 3?

Answer 28

oh we take the charges I forgot

Answer 29

9

Answer 30

6

Answer 31

**

Answer 32

good, 6

so the aluminiums have to sum to +6 and the oxygens have to sum to -6

see what you can get from that

Answer 33

0

Answer 34

good, but how many atoms of Al and O?

Answer 35

2 for al and 3 for o

Answer 36

good so you end up w/ Al2O3

Answer 37

oh okay so take the LCM and then determine how many of each we would need to get that LCM and then jut use that

Answer 38

yes

Answer 39

how would I Adjust the subscript on each cation and anion to balance the overall charge.

Answer 40

idk how your program works

try shift underscore or something

Answer 41

I mean how would I do num 2

Answer 42

we did the calculations to determine that it would take 2 aluminium and 3 oxygen atoms to make a neutral molecule

so you would write A2O3

Answer 43

oh okay so that woul dbe it for number 2

Answer 44

yes

Answer 45

Here's another example: iF YOU could just check how I did

Answer 46

you have +2 and -2, these already cancel out to 0

so just CaO

Answer 47

So i basically just did it the long way

Answer 48

yeah it's fine, just make sure to reduce at the end if possible

Answer 49

Name the compound CaBr2.

SOLUTION

The cation is calcium. The anion is from bromine, which becomes bromide. The correct name is calcium bromide

Answer 50

WOuldn't the 2 subscript count as anything . I thought it would make it di- something

Answer 51

nah that's only for nonmetal + nonmetal compounds

Answer 52

ohhh

Answer 53

HOw do you know all this :S

Answer 54

Like you have it all memorized and its soooo much material

Answer 55

idk I took honors chem + AP Chem + freshman chem so it's been reinforced a lot i gues

Answer 56

oh right, and your a chem major right

Answer 57

yes

Answer 58

Name the compound Ag3N.



This would be Silver nitride

Answer 59

yup

Answer 60

so this is the metal and nonmetal ones right?

Answer 61

yes

Answer 62

The full names for compounds containing metals that form more than one kind of cation have the form:

Answer 63

what does this mean: "That forms from more than one kind of cation"

Answer 64

well, you know how alkali metals/alkaline earth metals have set charges? like Ca will always make Ca2+?

there are some elements (mostly transition metals) that can have different charges depending on what they're attached to

Iron is a good example, it can be Fe2O3 (+3 charge) or FeO (+2 charge)

Answer 65

right

Answer 66

so these compound make the form

metal(charge in roman numerals) nonmetal+"ide" suffix

so using the other example, FeO (+2 charge) ---> iron(II) oxide

Answer 67

so its basically any compound that has cation elements right

Answer 68

then you would put the parentheses

Answer 69

like only for cations

Answer 70

yeah it's generally only cations that do this, I can't think of any anions that do this

Answer 71

oh i see, you mean any cations that have more than one charge participate in this

Answer 72

yeah. unfortunately you just have to know which cations do this but here are the major ones