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3 years ago

What is the criteria to place an element in a particular group?

Chemistry

1 answer:

emmainna [20.7K]3 years ago

4 0

Answer: The criteria to place elements into groups and periods lies in their atomic number

Explanation:

As we know that period is the horizontal rows of elements in the periodic table and groups are vertical column of elements in the periodic table.

In a period we place those elements that have same number of shells and in a group those elements are placed that have different number of shells and the number of shells increases from top to bottom in a periodic table

For example

Sodium having symbol Na, atomic number of sodium is eleven it's electronic configuration is 1s2,2s2,2p6,3s1, next to it in a period is places potassium having symbol,K, it's electronic configuration is 1s2,2s2,2p6,3s2.

Sodium and potassium both r placed in a period not in a group because both of these have same outer most shell, only the number of electron in outer most shell varies.

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A 100.0 g sample of sugar contains carbon, hydrogen, and oxygen. The sample contains 40.0 g of carbon and 53.3 g of oxygen. What

Lynna [10]

Answer:

I think this is it.

Explanation:

As all the mass of other molecules are given and we have to find the mass of hydrogen so total subtracted by carbon and oxygen.

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3 years ago

What carries electric current from the cell to the other components of a circuit.

Rasek [7]

Answer:

The different objects that make up a circuit are called components. A circuit must have a power source, such as a battery, and the current flows through a conductor, such as a wire.

Explanation:

I hope that was useful.

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3 years ago

You decide to clean the bathroom. You notice that the shower is covered in a strange green slime. You try

musickatia [10]

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Use either a vinegar, Borax, or bleach solution in a spray bottle to tackle the mold. Simply spray the solution on showers, baths, basins, tiles, grout, or caulking. Then use either a cleaning cloth or a toothbrush to remove the slime

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2 years ago

1. A solution is always a mixture (true or false)

lakkis [162]

Answer:

yes solution is always a mixture but not all mixtures are solution

Explanation:

A solution.is a homogeneous mixture of substance that have uniform composition throughout

And a mixture hVe twoo or more substances that are not chemically.combine

4 0

3 years ago

NH4NO3, whose heat of solution is 25.7 kJ/mol, is one substance that can be used in cold pack. If the goal is to decrease the te

makvit [3.9K]

Answer:

There are necessaries 35,2g of NH₄NO₃ per 100,0g of water to decrease the temperature of the solution from 25,0°C to 5,0°C

Explanation:

To decrease the temperature of the solution there are necessaries:

4,184J/g°C×(5,0°C-25,0°C)×(100,0g+X) = -Y

8368J + 83,68J/gX = Y (1)

Where x are grams of NH₄NO₃ you need to add and Y is the energy that you need to decrease the heat.

Also, the energy Y will be:

Y = 25700J/mol× $\frac{1mol}{80,043g}$ X

Y = 321J/g X (2)

Replacing (2) in (1)

8368J + 83,68J/g X = 321J/g X

8363J = 237,32J/gX

X = 35,2g

Thus, there are necessaries 35,2g of NH₄NO₃ per 100,0g of water to decrease the temperature of the solution from 25,0°C to 5,0°C

I hope it helps!

6 0

3 years ago