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2 years ago

11

Two students made a model of the world's tallest building, the Burj Khalifa in Dubai. The scale of the model is 1:400. The stude

nts' model has a height of 2.07 m. How tall is the real building? O A. 0.005 m O B. 400 m O C. 193 m O D. 828 m

1 answer:

Anna [14]2 years ago

4 0

Answer:D

Explanation:

828m

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The chemical mixture that composes our atmosphere is called ________.

Virty [35]

Answer: Air

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3 years ago

Define the term. Theory

Sonja [21]

Answer:

a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.

(from goo gle)

A explanation for something that doesn't seem to be answered completely, usually very implausible.

Explanation:

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3 years ago

A substance has a boiling point of 78 °C. Which of the following is true about the substance? (5 points) a It will also change f

vovangra [49]

Answer: If a substance has a boiling point of $78^{o}C$ then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.

Explanation:

The temperature at which vapor pressure of a liquid substance becomes equal to the atmospheric pressure is called boiling point of substance.

At the boiling point, liquid phase and vapor phase remains in equilibrium.

This means that as liquid phase changes into vapor phase and also vapor phase changes into liquid phase at the boiling point.

Thus, we can conclude that if a substance has a boiling point of $78^{o}C$ then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.

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2 years ago

What are some factors that might stop populations exponential growth?

ipn [44]

Economy - If there isn't a sustainable economy, it won't be able to support many people so instead they are limited.

Weather- If a place is too warm or too cold it can affect the population. The weather may be seen as harsh.

Government- If people are not agreeing with the government and are against, many will leave. They won't be able to withstand it.

Overpopulation- If there is too many people, they may restrict how many babies you can have and how many people can live there. China, a co

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3 years ago

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the boiling of water, and exp

Sedbober [7]

Answer:

ΔH > 0; ΔS >0; ΔG = 0

Not spontaneous when T < 100 °C;

Equilibrium when T = 100 °C

Spontaneous when T > 100 °C

Step-by-step explanation:

The process is

H₂O(ℓ) ⇌ H₂O(g)

ΔH > 0 (positive), because we must <em>add heat</em> to boil water

ΔS > 0 (positive), because changing from a liquid to a gas i<em>ncreases the disorder </em>

ΔG = 0, because the liquid-vapour equilibrium process is at <em>equilibrium</em> at 100 °C

ΔG = ΔH – TΔS

Both ΔH and ΔS are positive.

If T = 100 °C, ΔG =0. ΔH = TΔS, and the system is at equilibrium.

If T < 100 °C, the ΔH term will predominate, because T has decreased below the equilibrium value.

ΔG > 0. The process is not spontaneous below 100 °C.

If T > 100 °C, the TΔS term will predominate, because T has increased above the equilibrium value.

ΔG < 0. The process is spontaneous above 100 °C.

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3 years ago