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3 years ago

Which best explains how thermal energy is transferred when someone holds a hand above a fire?

Chemistry

1 answer:

san4es73 [151]3 years ago

8 0

Answer:

D)It is transferred by convection and radiation.

Explanation:

Convection can be regarded as a model of heat transfer involving the transfer of thermal energy via movement of a fluids such liquid or gas. It's a process whereby heat is transferred by movement of a heated fluid. Radiation can be regarded as a model of heat transfer involving the transfer of thermal energy via thermal emission.

Therefore, when someone holds a hand above a fire it heat transfer occur through radiation because it happens through emmision of the heat and also convection as gas.

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** ANSWER FAST I WILL MARK YOU BRAINLIEST AND GIVE 20 POINTS * * THIS IS A CHEMISTRY QUESTION SO PLEASE ONLY ANSWER IF YOU ARE G

Anna11 [10]

Answer:

$\boxed{\text{ B. Increase the temperature and decrease the pressure.}}$

Explanation:

Let's say the reaction is

R ⇌ 2P; endothermic

I like to consider heat as if it were a reactant or a product in a chemical equilibrium.

Another way to write the equilibrium would be

heat + R ⇌ 2P

According to Le Châtelier's Principle, when a stress is applied to a system at equilibrium, the system will respond in a way that tends to relieve the stress.

Let's consider each of the stresses in turn.

(i) Changing the temperature

If you want to increase the amount of product, you increase the temperature. The system will try to get rid of the added heat by shifting to the right, thus forming more product.

(ii) Changing the pressure

If R and P are liquids or solids or in aqueous solution, changing the pressure will have no effect. Something must be in the gas phase for a change in pressure to affect the position of equilibrium.

If P is a gas, the equilibrium is

heat + R ⇌ 2P(g)

Then, decreasing the pressure will produce more P. If you reduce the pressure, the system will respond by shifting to the right (the side with more gas molecules) to produce more P and bring the pressure back up

5 0

4 years ago

What is the role of shrimp with respect to salmon in him food chain

KiRa [710]

The answer is *B. Prey*

8 0

4 years ago

Read 2 more answers

If the volume occupied by the gas molecules shown below were doubled, what would happen to the pressure they exert? (Assume cons

AnnZ [28]

there's no picture here but I guess the answer would be:

considering the constant temperature, if you double the volume, the pressure would be halved.

like: volume is 2, pressure is 4

if 2×2, then:4÷2

3 0

4 years ago

A block has a mass of 30g and dimensions of 1.5cm by 4.8cm by 2.3 cm. Will the block float or sink in

zimovet [89]

The block will sink

Explanation:

In general, an object with a higher density than water will sink in it, and one with a lower density will float. Now, to know if the block will float or sink, the first step is to calculate the density of the block, and to do this, the volume and mass of the block are required.

Mass of the block: 30 grames

Volume of the block:

The volume of the block is not provided, but this can be found using the dimensions given.

V (Volume) = s (side) x s x s

V = 1.5 cm x 4.8 cm x 2.3 cm

V = 16.56 $cm^{3}$

Density of the block:

To find the density simply divide the mass into the volume

D (density) = M (Mass) ÷ V (Volume)

D = 30 grams ÷ 16.56 $cm^{3}$

D = 1. 811 grams/ $cm^{3}$

The density of the block is 1. 811 grams/ $cm^{3}$

Additionally, the density of the water is 1 gram/ $cm^{3}$ or 1 gram/mL. According to this, the density of the block is higher than the density of the water, and therefore this is the block sinks.

3 0

4 years ago

How are solids and liquids different than gases in terms of volume changes

Daniel [21]

They are different substances because in the weight and size, they are different.
in weight gas weighs nothing but every solid is different.
same with liquids.

6 0

3 years ago