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3 years ago

Ice usually forms on the top part of lakes not the bottom , the reason for this occurence is?

Chemistry

1 answer:

Bingel [31]3 years ago

5 0

Answer:

Ice is less dense than water because of the way it forms a hexagonal crystalline structure. Each water molecule consists of two hydrogen atoms bonded to the bottom of an oxygen atom. ... In the winter, temperatures in a lake get close enough to freezing that the colder water is less dense and floats to the top

Explanation:

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Elements placed in the same group have similar chemical properties. Which one of the following has different chemical property?

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Answer:

Na has the different chemical property

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2 years ago

In any atom, the size of the nucleus with respect to the size of

iragen [17]

Answer:

Size of the nucleus of an atom is very small as compared to the size of the atom.

According to Rutherford gold foil experiment, nucleus is very small in size as compared to the size of the atom as a whole. Nucleus is very hard, dense and positively charged which consists of protons and neutrons.

Explanation:

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2 years ago

A chemical reaction is occurring inside a beaker and the temperature of the beaker is monitored. What would the contents of the

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Answer:

The system is the Answer

Explanation:

System is the region which is taken into consideration.

While we perform a chemical reaction the system is the substance taken in the container.

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The beaker (the surface which separates the system from its surroundings) is said to be the boundary

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3 years ago

Element Y has two natural isotopes Y-63 (62.940 amu) and Y-65 (64.928 amu). Calculate the atomic mass of element Y, given the ab

djverab [1.8K]

Answer:

Average atomic mass = 63.553 amu.

Explanation:

Given data:

Abundance of Y-63 = 69.17%

Abundance of Y-65 = 100 - 69.17 = 30.83%

Atomic mass of Y-63 = 62.940 amu

Atomic mass of Y-65 = 64.928 amu

Atomic mass of Y = ?

Solution:

Average atomic mass= (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass= (62.940×69.17)+(64.928×30.83) /100

Average atomic mass = 4353.560 + 2001.730 / 100

Average atomic mass = 6355.29 / 100

Average atomic mass = 63.553 amu.

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3 years ago

The production of ammonia (NH3) under standard conditions at 25°C is represented by the following thermochemical equation. N2(g)

asambeis [7]

Answer:

44,901 kilo Joule heat is released when $1.663\times 10^4 g$ grams of ammonia is produced.

Explanation:

Moles of ammonia gas produced :

$\frac{1.663\times 10^4 g}{17 g/mol}=978.235 mol$

According to reaction, when 2 moles of ammonia are produced 9.18 kilo joules of energy is also released.

So, When 978.235 moles of ammonia gas is produced the energy released will be:

$\frac{-91.8 kJ}{2}\times 978.235 mol=-44,900.98 kJ\approx -44,901 kJ$

(negative sign indicates that energy is released as heat)

44,901 kilo Joule heat is released when $1.663\times 10^4 g$ grams of ammonia is produced.

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3 years ago

Ice usually forms on the top part of lakes not the bottom , the reason for this occurence is?​

Ice usually forms on the top part of lakes not the bottom , the reason for this occurence is?