hope this is correct
Answer:
D
Explanation:
Iron is the fourth most abundant element, by mass, in the Earth's crust. The core of the Earth is thought to be largely composed of iron with nickel and sulfur. The most common iron-containing ore is haematite, but iron is found widely distributed in other minerals such as magnetite and taconite.
Answer:
0.271 M NO₃⁻
Explanation:
To find the molarity of the nitrate ion (NO₃⁻), you need to (1) convert grams to moles (via molar mass), then (2) convert moles Al(NO₃)₃ to moles NO₃⁻, then (3) convert mL to L, and then (4) calculate the molarity. When (Al(NO₃)₃) dissolves in water, it dissociates into 3 nitrate ions. The final answer should have 3 sig figs.
(Steps 1 + 2)
Molar Mass (Al(NO₃)₃): 26.982 g/mol + 3(14.007 g/mol) + 9(15.998 g/mol)
Molar Mass (Al(NO₃)₃): 212.985 g/mol
1 Al(NO₃)₃ = 1 Al³⁺ and 3 NO₃⁻
6.25 g Al(NO₃)₃ 1 mole 3 moles NO₃⁻
------------------------- x ----------------- x ----------------------- = 0.0880 moles NO₃⁻
212.985 g 1 mole Al(NO₃)₃
(Steps 3 + 4)
325.0 mL / 1,000 = 0.3250 L
Molarity = moles / volume
Molarity = 0.0880 moles / 0.3250 L
Molarity = 0.271 M
Answer:
Electrons
Explanation:
The breaking and forming of bonds between atoms in substances results in changes in the number of electrons in the substance.
- Atoms combined in order to share, gain or lose electrons for it to be stable.
- The noble gases have a set up configuration which makes them stable.
- All atom tend to mimic the noble gases.
1) Data:
T₁ = <span>
21°C
</span>
<span>T₂ = 51°C.
</span>
<span>V₁ = V₂ = 15.6 L
</span>
<span>P₁ = 249 kPa.
</span>
<span>Pb = 269 kPa.
</span>
<span>Questions:
</span>
• n = ?
• P₂ = ?
• Will the tires burst at the peak temperature? Explain.
• To what pressure should the tire pressure be reduced before starting
the ride to avoid bursting of the tires in the desert heat? (Assume no
significant change in tire volume.)
Pi = ?
2) Formula:
PV = nRT
P₁ / T₁ = P₂ / T₂
3) Solution
i) n
P₁V₁ = nRT ⇒ n = P₁V₁ / [RT₁]
n = 249 kPa × 15.6 liter / [8.314 (liter-kPa / mol-K) × (21 + 273.15K) ] =
n = 1.588 mol
ii) P₂
P₂ = P₁ T₂ / T₁ = 249 kPa (50 + 273.15 K) / (21 + 273.15K) = 273.5 kPa
iii) Tires will burst, since P₂ > Pb
iv) Pi
Pi / T₁ = Pb / T₂
Pi = Pb T₁ / T₂ = 269 kPa (21 + 273.15K) / (50 + 273.15K) = 244.9 kPa
The pressure shoul to be reduced to less than 244.9 kPa before starting to avoid the <span> bursting of the tires in the desert heat.</span>
Answer:
I^ -1 configuration is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6
Explanation:
The electron configuration of iodine is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p5, but with the addition of an electron it gains another other to make it 5p6.
