All categories

3 years ago

Why k has more shielding effect than Na?

Chemistry

1 answer:

lara [203]3 years ago

8 0

Explanation:

As the charge of all electrons are equal, the repulsive force exerted by each of them is also going to be equal. So, as K has more electrons repulsing its valence electron than Na, it has greater electron shielding.

You might be interested in

An igneous rock that _____ is made of really small mineral crystals. A. cools rapidly B. crystallizes slowly C. undergoes extrem

Elina [12.6K]

Answer: An igneous rock that cools rapidly is made of really small mineral crystals.

Explanation:

The layers inside the earth are hot enough to melt a rock. The liquid or molten rock is known as magma.

When a molten rock cools and solidifies, it results in the formation of an igneous rock.

The slow cooling of magma will result in the formation of an igneous rock with large crystals. Whereas, rapid cooling of lava will result in the formation of an igneous rock with small crystals.

Thus, it can be concluded that an igneous rock that cools rapidly is made of really small mineral crystals.

6 0

4 years ago

A 1.8 g sample of octane C8H18 was burned in a bomb calorimeter and the temperature of 100 g of water increased from 21.36 C to

melomori [17]

Answer:

HEAT OF COMBUSTION PER GRAM OF OCTANE IS 1723.08 J OR 1.72 KJ/G OF HEAT

HEAT OFF COMBUSTION PER MOLE OF OCTANE IS 196.4 KJ/ MOL OF HEAT

Explanation:

Mass of water = 100 g

Change in temperature = 28.78 °C - 21.36°C = 7.42 °C

Heat capcacity of water = 4.18 J/g°C

Mass of octane = 1.8 g

Molar mass of octane = C8H18 = (12 * 8 + 1 * 18) g/mol= 96 + 18 = 114 g/mol

First is to calculate the heat evolved when 100 g of water is used:

Heat = mass * specific heat capacity * change in temperature

Heat = 100 * 4.18 * 7.42

Heat = 3101.56 J

In other words, 3101.56 J of heat was evolved from the reaction of 1.8 g octane with water.

Heat of combustion of octane per gram:

1.8 g of octane produces 3101.56 J of heat

1 g of octane will produce ( 3101.56 * 1 / 1.8)

= 1723.08 J of heat

So, heat of combustion of octane per gram is 1723.08 J

Heat of combustion per mole:

1.8 g of octane produces 3101.56 J of heat

1 mole of octane will produce X J of heat

1 mole of octane = 114 g/ mol of octane

So we have:

1.8 g of octane = 3101.56 J

114 g of octane = (3101.56 * 114 / 1.8) J of heat

= 196 432.13 J

= 196. 4 kJ of heat

The heat of combustion of octane per mole is 196.4 kJ /mol.

Mass of water = 100 g

Change in temperature = 28.78 °C - 21.36°C = 7.42 °C

Heat capcacity of water = 4.18 J/g°C

Mass of octane = 1.8 g

Molar mass of octane = C8H18 = (12 * 8 + 1 * 18) g/mol= 96 + 18 = 114 g/mol

First is to calculate the heat evolved when 100 g of water is used:

Heat = mass * specific heat capacity * change in temperature

Heat = 100 * 4.18 * 7.42

Heat = 3101.56 J

8 0

3 years ago

1. Fill in the blanks. Example: A nitrogen atom takes on a 3- charge when it forms an anion and becomes nitride. a. A magnesium

Tema [17]

Answer: a. +2, cation and magnesium ion .

b. -1, anion, chloride

c. -2, anion, oxide

d. +1. cation , potassium ion

Explanation:

When an atom accepts an electron negative charge is created on atom and is called as anion.

When atom loses an electron positive charge is created on atom and is called as cation.

Magnesium (Mg) with atomic number of 12 has electronic configuration of 2,8,2 and thus it can lose 2 electrons to form $Mg^{2+}$ cation and becomes magnesium ion.

Chlorine (Cl) with atomic number of 17 has electronic configuration of 2,8,7 and thus it can gain 1 electron to form $Cl^{-}$ anion and becomes chloride.

Oxygen (O) with atomic number of 8 has electronic configuration of 2,6 and thus it can gain 2 electrons to form $O^{2-}$ anion and becomes oxide.

Potassium (K) with atomic number of 19 has electronic configuration of 2,8,8,1 and thus it can lose 1 electron to form $K^{+}$ cation and becomes potassium ion.

3 0

3 years ago

Why are the elements 57 through 70, and 89 through 102, found separately at the bottom of the Periodic table?

-Dominant- [34]

<span>Elements from 57 to 71 are Lanthanoids and from 89 to 103 are Actinoids. Simply I would say Actinoids have less similarity in chemical properties than Lanthanoids. On the other hands, Actinoids have randomized chemical strutural bonds.</span>

6 0

3 years ago

Read 2 more answers

A reaction in which two ions switch places is which type of reaction?

AURORKA [14]

A reaction in which two ions switch places is called double-displacement reaction.

Explanation:

Double displacement reaction usually takes place between two positive ions or two negative ions. When anions or cations of totally different compounds change places, two totally different compounds are formed.

<u>Syntax for double displacement reaction: </u>

AB + CD --> AD + BC

It can also be defined in simple terms as the reaction in which exchange of ions takes place is called double displacement reaction.

The chemical reaction is as follows:

NaOH(aq) + HCl(aq) --> NaCl(aq) + H2O (l)

6 0

3 years ago

Why k has more shielding effect than Na?​

Why k has more shielding effect than Na?