Which sequence of atomic numbers represents elements that have similar chemical properties?

Please help this is so hard 1: Why is the sky blue?

kolezko [41]

Answer:

1. As white light passes through our atmosphere, tiny air molecules cause it to 'scatter'. Therefore, blue light is scattered more than red light and the sky appears blue during the day.

2. We can see the moon during the day for the same reason we see the moon at night. The surface of the moon is reflecting the sun's light into our eyes. When we see the moon during the day it's because the moon is in the right spot in the sky and it's reflecting enough light to be as bright, or brighter, than the sky.

3. At eight pounds per gallon, that's another 38,593,169,564 pounds of water in the air. Add it all up, and the total weight of our sky is 12,107,415,382,493,169,564 pounds, more than 12 quintillion pounds!

4. 5.972 × 10^24 kg

5. Four forces keep an airplane in the sky. They are lift, weight, thrust and drag. Lift pushes the airplane up.

6. Water is wet, in the sense of being a liquid which flows easily, because its viscosity is low, which is because its molecules are rather loosely joined together.

7. Rainbows are formed when sunlight is scattered from raindrops into the eyes of an observer. The lower the sun in the sky the more of an arc of a rainbow the viewer will see. Rain, fog or some other source of water droplets must be in front of the viewer.

8. Birds can sit on power lines and not get electric shocks because the electricity is always looking for a way to get to the ground. The birds are not touching the ground or anything in contact with the ground, so the electricity will stay in the power line.

Explanation:

4 0

3 years ago

Read 2 more answers

Calculate the heat energy required to melt 4kg of ice when the specific latent heat of fusion of water is 334,000 J/kg.

Setler79 [48]

Taking into account the definition of calorimetry and latent heat, the heat energy required to melt 4 kg of ice when the specific latent heat of fusion of water is 334,000 $\frac{J}{kg}$ is 1,336 kJ.

<h3>Calorimetry</h3>

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

<h3>Latent heat</h3>

Latent heat is defined as the energy required by a quantity of substance to change state.

When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.

The heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to

Q = m×L

where L is called the latent heat of the substance and depends on the type of phase change.

<h3>Heat energy required to melt ice</h3>

In this case, you know:

m= 4 kg
L= specific latent heat of fusion of water= 334,000 $\frac{J}{kg}$

Replacing in the expression for latent heat:

Q = 4 kg× 334,000 $\frac{J}{kg}$

Solving:

<u><em>Q= 1,336,000 J= 1,336 kJ </em></u>(being 1,000 J= 1 kJ)

Finally, the correct answer is the first option: the heat energy required to melt 4 kg of ice when the specific latent heat of fusion of water is 334,000 $\frac{J}{kg}$ is 1,336 kJ.

Learn more about calorimetry:

<u>brainly.com/question/14057615?referrer=searchResults</u>

<u>brainly.com/question/24988785?referrer=searchResults</u>

<u>brainly.com/question/21315372?referrer=searchResults</u>

<u>brainly.com/question/13959344?referrer=searchResults</u>

<u>brainly.com/question/14309811?referrer=searchResults</u>

<u>brainly.com/question/23578297?referrer=searchResults</u>

7 0

2 years ago

Read 2 more answers

Janet hikes a trail at a local forest each day. The trail is 3.6 miles long, and she hiked five days in the past week. How many

anastassius [24]