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3 years ago

How did the discovery of isotopes help to lead to a revised model of atomic structure?

1 answer:

8 0

Dalton postulated that atoms of the same elements had the same mass while atoms of different elements had different masses.

The discovery of isotopes revealed that atoms of the same element did not necessarily have same masses, they could have different masses.

Therefore, the modern periodic table that we use nowadays contains the average atomic mass of all the isotopes found for a given element.

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PLEASEEEEEEEEEEEE HELPPPPPPPP I BEGGGGG FOR HELPPPPP

Elza [17]

Answer: There are $21.08\times 10^{23}$ molecules in 63.00 g of $H_2O$

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{63.00g}{18g/mol}=3.5moles$

1 mole of $H_2O$ contains = $6.023\times 10^{23}$ molecules

Thus 3.5 moles of $H_2O$ contains = $\frac{6.023\times 10^{23}}{1}\times 3.5=21.08\times 10^{23}$ molecules.

There are $21.08\times 10^{23}$ molecules in 63.00 g of $H_2O$

3 0

3 years ago

How does the location and design of a house can help control temperature?

Anestetic [448]

Answer:

See detailed explanation.

Explanation:

Hello.

In this case, since each place has specific conditions of temperature, humidity, altitude and others, it is important for the companies building houses to consider all of those factors because they could wear out or affect the customer's lifestyle as the years go by.

More specifically, for temperature, since customers tend to complain and concern about it, there are some strategies in order to control it:

- In terms of location, it is possible to locate the house near to threes covering the sun, build it in a higher altitude since the higher altitude the lower the environmental temperature or just look for a place wherein the temperature is almost constant, for instance, south America.

- In terms of design, it is possible to build the walls and roofs with isolating materials which very likely to keep the inner part of the house from high temperatures or just installing heaters inside them.

Of course, there may be more strategies in order to control it.

Best regards.

6 0

3 years ago

A student practicing for a cross country meet runs 250 m in 30s what is her average speed

aev [14]

Answer:

Speed = 8.34 m/s

Explanation:

Given =

Distance = 250 meters

Time = 30 seconds

Solution =

Speed = Distance / Time

Speed = 250/30

Speed = 8.3333333 m/s.

Speed = 8.34 m/s

3 0

3 years ago

Read 2 more answers

Will Mark brainliest fro correct answer!!!!<br><br> Please answer in the picture chemistry

tiny-mole [99]

Answer:

look at the graph

Explanation:

We know that as temperature increases, solubility increases.So, when there is a rise in temperature, as more solute become dissolved, the saturation point will be lifted and more amount of solute will be needed to reach saturation.

Here, when the temperature was 20oC, 38 g of salt was needed for saturation. As the temperature is increased by 15oC, at 35oC more amount of salt was needed to reach saturation(45g). So a 15oC rise in temperature caused a 7 g rise in the amount of salt needed for saturation. So, if temperature is increased additionally through 10oC, an approximate 4.5 g of salt will be needed more to reach the saturation. That is at 45oC, the amount of salt at saturation will be approximately 49.5 g.

So, the temperature and solubility as well as temperature and amount of salt at saturation are linearly related(directly proportional)

6 0

2 years ago

1. ____ is the measure of the pull of gravity on an object.

Vikki [24]

1. weight

2. gravity

3. mass, far(distance)

4. weight

5. mass, ?

5 0

3 years ago