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3 years ago

Which of the following groups in the periodic

1 answer:

7 0

Elements of Group 1 and group 2 in the periodic table contain elements so reactive that they are never found in the free state

<u>Explanation</u>:

The metals in group 1 of periodic table consisting of 'alkali metals' which include lithium, potassium, sodium, rubidium, Francium and caesium. They are highly reactive because they have low ionisation energy and larger radius. The group 2 metals consist of 'alkaline earth metals' which include calcium, strontium, barium, beryllium, radium and magnesium. These alkaline earth metal have +2 oxidation number, hence are highly reactive.

These both group metals are mostly reactive and so are never found in a free state. When they are exposed to air they would immediately react with oxygen. Hence, are stored in oils to avoid oxidation.

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Very quick oxidation reactions result in _____.

Oksana_A [137]

<span>Very quick oxidation reactions result in combustion. Combustion happens when oxidation is fast. An example of combustion is the light batteries. We know that it is really dangerous if we will burn it because it has a fast oxidation process that can cause fire and its gas will explode.</span>

4 0

3 years ago

**PLATO QUESTION, PLEASE ANSWER CORRECTLY**

Ivenika [448]

The corect answers will be:
1) A
2) B
3) D

Hope this helped :)

7 0

3 years ago

Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for t

mihalych1998 [28]

Answer:

$\Delta Tfp_{NaCl}= -14.0\°C\\\\\Delta Tfp_{CaCl_2}=-11.1\°C$

Explanation:

Hello!

In this case, since the freezing point depression caused by the addition of a solute, we use the following formula:

$\Delta Tfp= i*m*Kfp$

Thus, we first need to compute the molality of each solute, as shown below:

$m_{NaCl}=\frac{220.g/(58.44g/mol)}{1.00kg} =3.76m\\\\m_{CaCl_2}=\frac{220.g/(110.98g/mol)}{1.00kg} =1.98m$

Next, since NaCl has two ionic species, one Na⁺ and one Cl⁻, and CaCl₂ three, one Ca²⁺ and two Cl⁻, the van't Hoff's factors are 2 and 3 respectively, therefore the freezing point depressions turn out:

$\Delta Tfp_{NaCl}= 2*3.76m*-1.86\°C/m=-14.0\°C\\\\\Delta Tfp_{CaCl_2}= 3*1.98m*-1.86\°C/m=-11.1\°C$

It means that CaCl₂ is still better than NaCl because produces involves a higher melting point for the ice, so it would melt faster.

Best regards!

3 0

3 years ago

Which change to an object would double its kinetic energy?

Rina8888 [55]

Answer:

Increasing its mass to twice its original value

Explanation:

Pls mark me brainliest

4 0

3 years ago

Electrolysis of molten lead bromide is carried out.

bearhunter [10]

Answer:

Read Below

Explanation:

Electrolysis is not possible with solid lead (II) bromide. This is because the ions are held in a three-dimensional lattice, unable to move freely to the electrodes. Melting enables the ions to become mobile and to travel to the respective electrodes.

The bulb won't glow when the electrodes are embedded in solid lead bromide. The bulb will glow when the material surrounding the electrodes is molten lead bromide. When an ionic compound is in the molten (liquid) form the positive and negative ions are free to move around.

Hopes this Helps :D

Brainiest Please

5 0

3 years ago