<span>Answers are:
-4 for C in CH4, because carbon has greater electronegativity than hydrogen and he attracts shared electrons.
</span><span>+4 for C in CO2, because carbon has smaller electronegativity than oxygen.
</span><span>+1 for H in both CH4 and H2O, because hydrogen has amaller electronegativity than both carbon and oxygen.
</span>
(d) Density of Benzene: 0.8786 g/cm cubed
(m) Mass: 20.00g
Formula to solve (v) volume of benzene: V=m/d
V=20g / 0.8786g/cm cubed
Answer: Volume of benzene is: 22.8 cm cubed
Explanation: Well, density is mass divided volume. In this, it is what the volume is. All you need is mass divided by density. Hope this helps!
17.8 g of sodium perchlorate contains 8.73 × 10²² Na⁺ ions, 8.73 × 10²² ClO₄⁻ ions, 8.73 × 10²² Cl atoms and 3.49 × 10²³ O atoms.
First, we will convert 17.8 g of NaClO₄ to moles using its molar mass (122.44 g/mol).

Next, we will convert 0.145 moles to molecules of NaClO₄ using Avogadro's number; there are 6.02 × 10²³ molecules in 1 mole of molecules.

NaClO₄ is a strong electrolyte that dissociates according to the following equation.
NaClO₄ ⇒ Na⁺ + ClO₄⁻
The molar ratio of NaClO₄ to Na⁺ is 1:1. The number of Na⁺ in 8.73 × 10²² molecules of NaClO₄ is:

The molar ratio of NaClO₄ to ClO₄⁻ is 1:1. The number of ClO₄⁻ in 8.73 × 10²² molecules of NaClO₄ is:

The molar ratio of ClO₄⁻ to Cl is 1:1. The number of Cl in 8.73 × 10²² ions of ClO₄⁻ is:

The molar ratio of ClO₄⁻ to O is 1:1. The number of O in 8.73 × 10²² ions of ClO₄⁻ is:

17.8 g of sodium perchlorate contains 8.73 × 10²² Na⁺ ions, 8.73 × 10²² ClO₄⁻ ions, 8.73 × 10²² Cl atoms and 3.49 × 10²³ O atoms.
You can learn more Avogadro's number here: brainly.com/question/13302703
Answer:
And if someone calls you dense, they think nothing can get into your thick skull. Dense comes from the Latin densus which means thick and cloudy. In general, the word means packed tight and gives the sense that something is difficult to get through.
Explanation: Look it up :)