Answer:
Protons: 79
Electrons: 78
Explanation:
1. The number of protons is the atomic number (The atomic number for Au on the periodic table is 79)
2. Since the charge is +1 (positive) it means that there's one more proton than electrons. So, 79-1 = 78 electrons
Answer:
Ionic bonds hold charged particles in solid NaCl together, such that they are unable to move or conduct electricity.
Explanation:
Consider an electric current that flows through a conductor: charge moves in a uniform direction from one end of the conductor towards the other.
Thus, there are two conditions for a substance to conduct electricity:
- The substance shall contain charged particles, and
- These charged particles shall be free to move across the substance.
A conductor of electricity shall meet both requirements.
Now, consider the structure of solid NaCl 
. NaCl is an ionic compound. It contains an ocean of oppositely charged ions:
- Positive
ions, and - Negative
ions.
Ions carry charge. Thus, solid NaCl contains charged particles and satisfies the first condition.
Inside solid NaCl , electrostatic attractions ("ionic bonds") between the oppositely charged ions hold these ions in rigid ionic lattices. These ions are unable to move relative to each other. As a result, they cannot flow through the solid to conduct electricity. Under solid state, NaCl is unable to satisfy the second condition.
As a side note, melting NaCl into a liquid breaks the ionic bonds and free the ions from the lattice. Liquid NaCl is a conductor of electricity.
Answer:
pH = 12.22
Explanation:
<em>... To make up 170mL of solution... The temperature is 25°C...</em>
<em />
The dissolution of Barium Hydroxide, Ba(OH)₂ occurs as follows:
Ba(OH)₂ ⇄ Ba²⁺(aq) + 2OH⁻(aq)
<em>Where 1 mole of barium hydroxide produce 2 moles of hydroxide ion.</em>
<em />
To solve this question we need to convert mass of the hydroxide to moles with its molar mass. Twice these moles are moles of hydroxide ion (Based on the chemical equation). With moles of OH⁻ and the volume we can find [OH⁻] and [H⁺] using Kw. As pH = -log[H⁺], we can solve this problem:
<em>Moles Ba(OH)₂ molar mass: 171.34g/mol</em>
0.240g * (1mol / 171.34g) = 1.4x10⁻³ moles * 2 =
2.80x10⁻³ moles of OH⁻
<em>Molarity [OH⁻] and [H⁺]</em>
2.80x10⁻³ moles of OH⁻ / 0.170L = 0.01648M
As Kw at 25°C is 1x10⁻¹⁴:
Kw = 1x10⁻¹⁴ = [OH⁻] [H⁺]
[H⁺] = Kw / [OH⁻] = 1x10⁻¹⁴/0.01648M = 6.068x10⁻¹³M
<em>pH:</em>
pH = -log [H⁺]
pH = -log [6.068x10⁻¹³M]
<h3>pH = 12.22</h3>
I think the answer is A but i'm not sure
