Answer:
Option b. Decomposition
Followed by a reduction process using charcoal
Explanation:
Lead can be obtained from lead nitrate by thermal decomposition of lead nitrate as shown below:
2Pb(NO3)2 —> 2PbO + 4NO2 + O2
The PbO obtained is reduced by charcoal(C) to obtain the metallic Pb as shown below:
2PbO + C —> Pb + CO2
Answer:
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth's surface.
Answer:
The required volume is 1.6 x 10³mL.
Explanation:
When we want to prepare a dilute solution from a concentrated one, we can use the dilution rule to find out the required volume to dilute. This rule states:
C₁ . V₁ = C₂ . V₂
where,
C₁ and V₁ are the concentration and volume of the concentrated solution
C₂ and V₂ are the concentration and volume of the dilute solution
In this case, we want to find out V₁:
C₁ . V₁ = C₂ . V₂

Answer:
- <u><em>1.7 × 10³ kg of ore.</em></u>
Explanation:
Call X the amount of aluminum ore mined to produce 1.0 × 10³ kg the aluminum metal.
Then, taking into account the yield of the reaction (82 % = 0.82) and the percent of aluminun in the ore (71% = 0.71), you can write the following equation:
- X × 71% × 82% = 1.0 × 10³ kg
↑ ↑ ↑ ↑
(mass of ore) (% of Al in the ore) (yield) ( Al metal to obtain)
You must just simplify, solve and compute:
- X = 1,000 / (0.71 × 0.82) = 1,000 / 0.5822 = 1,717.6 Kg
Round to two significant figures; 1,700 kg = 1.7 × 10³ kg of ore ← answer.
Answer: Option (b) is the correct answer.
Explanation:
Kinetic energy is defined as the energy obtained by the molecules of an object due to their motion.
Also, it is known that kinetic energy is directly proportional to temperature.
Mathematically, K.E = 
where, T = temperature
Whereas potential energy is defined as the energy obtained by an object due to its position.
Mathematically, P.E = mgh
where, m = mass
g = acceleration due to gravity
h = height
Therefore, in the given curve when temperature remains constant then kinetic energy of molecules will also remain.
Hence, we can conclude that the segment QR represents an increase in the potential energy, but no change in the kinetic energy.