How many moles of atoms are in 8.1 × 10^5
g
Pb?
Answer in units of mol.

3900 mol Pb

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

8.1 × 10⁵ g Pb

Step 2: Identify Conversions

Molar Mass of Pb - 207.2 g/mol

Step 3: Convert

= 3909.27 mol Pb

Step 4: Check

We are given 2 sig figs. Follow sig fig rules and round.

3909.27 mol Pb ≈ 3900 mol Pb

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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~ trueboss72