Answer:
B, C
Explanation:
The atoms or ions with the valid Lewis dot structures are B and C.
In A;
The Lewis structure of the carbon is correct. Each of the four dots represent the four valence electrons.
The nitrogen with one dot on top, left and to the bottom and has a charge of minus 3 is wrong. For it to have a charge of -3 it must have 8 lewis dots ( two on the top, right, bottom and to the left)
The nitrogen with four dots (on top, right, bottom and to the left) is wrong.
In B;
An oxygen has two dots on top and bottom and one dot to the left and to the right. This is correct , the 6 dots represent the valence electrons of oxygen.
In C;
A carbon has two dots on top, right, bottom and to the left and a charge of plus four. This is correct because the charge indicates that it has gained four extra electrons so its valence electrons is now 8.
In D;
An oxygen has two dots on top, left and to the bottom and a charge of minus 2. This is wrong because the lewis dots are incomplete. Two dots are missing.
we are given the the two reactants: AgNO3 and Na2CO3 and is asked to write a balanced equation and a net ionic equation for the reaction of the two. This is a double-replacement reaction:
2AgNO3 (aq)+ Na2CO3 (aq)= Ag2CO3 + 2NaNo3 (aq)
2 Ag + + 2 N03- + 2Na+ + CO32- = Ag2CO3 + 2 Na+ 2NO3-
cancelling the spectator ions, 2Ag + + CO32- = Ag2CO3
Answer:
1. 0.207 moles
2. 6.99 moles
3. 4.20 moles
4. 4.65 moles
5. 2.221 × 10²⁴ atoms
6. 2.221 × 10²⁴ atoms
7. 4.979 × 10^18 atoms
Explanation:
The number of moles and atoms can be calculated using the Avagadro's number, which is 6.02 × 10^23 atoms.
mole = number of atoms ÷ Avagadro's number.
1. Mole = 1.25 x 10²³ ÷ 6.02 × 10^23
mole of Boron = 0.207 × 10(23-23)
= 0.207 × 10^0
= 0.207 moles
2. Mole = 4.21 x 10²⁴ ÷ 6.02 × 10^23
mole of Aluminum = 0.699 × 10(24-23)
= 0.699 × 10^1
= 6.99 moles
3. Mole = 2.53 x 10²⁴ ÷ 6.02 × 10^23
mole of Argon = 0.420 × 10(24-23)
= 0.420 × 10^1
= 4.20moles
4. Mole = 2.80 x 10²⁴ ÷ 6.02 × 10^23
mole of Hydrogen = 0.465 × 10(24-23)
= 0.465 × 10^1
= 4.65 moles
5. Number of atoms of Na = 3.69 × 6.02 × 10²³
= 22.21 × 10²³
= 2.221 × 10²⁴ atoms
6. Number of atoms of Na = 3.69 × 6.02 × 10²³
= 22.21 × 10²³
= 2.221 × 10²⁴ atoms
7. Number of atoms of Co = 8.27 x 10⁻⁶ moles × 6.02 × 10²³ atoms
= 49.79 × 10^17
= 4.979 × 10^18 atoms