For the indicated atom in each of the following molecules or ions, give the number and arrangement of the electron pairs around that atom.

(a) As in AsO43-
number:
arrangement:
linear
bent
trigonal planar
square planar
tetrahedral

(b) Se in SeO42-
number:
arrangement:

linear
bent
trigonal planar
square planar
tetrahedral

(c) S in H2S
number:
arrangement:

linear
bent
trigonal planar
square planar
tetrahedral

could u check if im right:
a. As in AsO43-

for number its 3
arrangement is tetrahedral

b. Se in SeO42-
# is 2
arrangement is tetrahedral

c. S in H2S
# is 1
arrangement is linear

pls help

You can find most of these if you will Google them.

(a) As in AsO43-

The number of electron pairs around the As atom is 4.
The arrangement is tetrahedral.

(b) Se in SeO42-
The number of electron pairs around the Se atom is 4.
The arrangement is tetrahedral.

(c) S in H2S
The number of electron pairs around the S atom is 2.
The arrangement is bent.

Your answers are partially correct. For (c) S in H2S, the arrangement is bent, not linear. The rest of your answers for (a) and (b) are correct.

To determine the number and arrangement of electron pairs around a specific atom in a molecule or ion, follow these steps:

Step 1: Determine the Lewis structure of the molecule or ion. This includes identifying the central atom and determining the number of valence electrons for each atom.

Step 2: Calculate the total number of valence electrons by summing up the valence electrons of all atoms in the molecule or ion. Take into consideration any charges present.

Step 3: Assign lone pairs and bonding pairs to each atom in the Lewis structure. Lone pairs are non-bonding pairs of electrons, while bonding pairs are shared between atoms.

Step 4: Count the number of bonding pairs and lone pairs associated with the specific atom you are interested in.

Step 5: Determine the electron pair arrangement based on the number of electron pairs. The possible arrangements are linear, bent, trigonal planar, square planar, and tetrahedral.

Now let's determine the number and arrangement of electron pairs around the indicated atoms in each of the given molecules or ions:

(a) As in AsO43-:
- Step 1: The central atom is As (arsenic), and we have 4 oxygen atoms bonded to it.
- Step 2: As has 5 valence electrons, while each oxygen has 6 valence electrons. Considering the charge of AsO43-, we have a total of (5 + 4 × 6 + 3 = 32) valence electrons.
- Step 3: Draw the Lewis structure and assign lone pairs and bonding pairs.
- Each oxygen atom is bonded to As, resulting in a total of 4 bonding pairs.
- The remaining 12 electrons are distributed as 3 lone pairs on each oxygen atom.
- Step 4: We are interested in the As atom. It has 4 bonding pairs and 0 lone pairs.
- Step 5: With 4 electron pairs, the arrangement is tetrahedral.

So the number of electron pairs around As in AsO43- is 4, and the arrangement is tetrahedral.

(b) Se in SeO42-:
- Step 1: The central atom is Se (selenium), and we have 4 oxygen atoms bonded to it.
- Step 2: Se has 6 valence electrons, while each oxygen has 6 valence electrons. Considering the charge of SeO42-, we have a total of (6 + 4 × 6 + 2 = 32) valence electrons.
- Step 3: Draw the Lewis structure and assign lone pairs and bonding pairs.
- Each oxygen atom is bonded to Se, resulting in a total of 4 bonding pairs.
- The remaining 18 electrons are distributed as 3 lone pairs on each oxygen atom.
- Step 4: We are interested in the Se atom. It has 2 bonding pairs and 0 lone pairs.
- Step 5: With 2 electron pairs, the arrangement is linear.

So the number of electron pairs around Se in SeO42- is 2, and the arrangement is linear.

(c) S in H2S:
- Step 1: The central atom is S (sulfur), and we have 2 hydrogen atoms bonded to it.
- Step 2: S has 6 valence electrons, while each hydrogen has 1 valence electron. Therefore, we have (6 + 2 × 1 = 8) valence electrons.
- Step 3: Draw the Lewis structure and assign lone pairs and bonding pairs.
- Each hydrogen atom is bonded to S, resulting in a total of 2 bonding pairs.
- The remaining 4 electrons are distributed as 1 lone pair on the sulfur atom.
- Step 4: We are interested in the S atom. It has 2 bonding pairs and 1 lone pair.
- Step 5: With 3 electron pairs, the arrangement is trigonal planar.

So the number of electron pairs around S in H2S is 3, and the arrangement is trigonal planar.

Now you can verify if your answers are correct based on the provided explanations.