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2 years ago

True or False Helium belongs to Noble Metals

Chemistry

2 answers:

Lostsunrise [7]2 years ago

6 0

Answer:

This answer is "True"

Vlada [557]2 years ago

6 0

The answer would be *true*

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When a heavy atom is split in a fission reaction, the daughter nuclei that form have higher binding energies than the parent nuc

AlladinOne [14]

True because the parents have less energy now

7 0

2 years ago

Read 2 more answers

Commercial cold packs often contain solid NH4NO3 and a pouch of water. The temperature of the pack drops as the NH4NO3 dissolves

Yanka [14]

Answer: b. $\Delta H_{soln}$ is positive and $\Delta S_{soln}$ is positive.

Explanation:-

As the temperature of the pack drops, the energy has been absorbed from the pack for dissolution of $NH_4NO_3$ in water. Thus as the energy has been absorbed in the reaction, the reaction is endothermic and the change in enthalpy i.e. $\Delta H_{soln}$ is positive.

The entropy is the measure of degree of randomness. The entropy increases when the randomness increases and the entropy decreases when the randomness decreases. When a substance dissolves in water, it dissociate into ions and hence the randomness increases thus the change in entropy i.e. $\Delta S_{soln}$ is positive.

$NH_4NO_3\rightarrow NH_4^++NO_3^-$

7 0

2 years ago

If the molecule could move upward without colliding with other molecules, then how high would it go before coming to rest? Give

tankabanditka [31]

The maximum height at which nitrogen molecule will go before coming to rest is 14 kilometers.

Given:

The nitrogen gas molecule with a temperature of 330 Kelvins is released from Earth's surface to travel upward.

To find:

The maximum height of a nitrogen molecule when released from the Earth's surface before coming to rest.

Solution:

The maximum height attained by nitrogen gas molecule = h
The temperature of nitrogen gas particle = T = 330 K

The average kinetic energy of the gas particles is given by:

$K.E=\frac{3}{2}K_bT\\\\K.E=\frac{3}{2}\times 1.38\times 10^{-23} J/K\times 330 K\\\\K.E=6.381\times 10^{-21} J$

The nitrogen molecule at its maximum height will have zero kinetic energy as all the kinetic energy will get converted into potential energy

The potential energy at height h = $P.E = 6.381\times 10^{-21} J$
Molar mass of nitrogen gas = 28.0134 g/mol
Mass of nitrogen gas molecule = m

$m= \frac{ 28.0134 g/mol}{6.022\times 10^{23} mol^{-1}}=4.652\times 10^{-23} g\\\\1g=0.001kg\\\\m=4.652\times 10^{-23}\times 0.001 kg\\\\=4.652\times 10^{-26} kg$

The acceleration due to gravity = g = 9.8 m/s^2
The maximum height attained by nitrogen gas molecule = h
The potential energy is given by:

$P.E=mgh$

$6.381\times 10^{-21} J=4.652\times 10^{-26} kg\times 9.8 m/s^2\times h\\\\h=\frac{6.381\times 10^{-21} J}{4.652\times 10^{-26} kg\times 9.8 m/s^2}\\\\h=13,996.6 m\\\\1 m = 0.001 km\\\\h=13,996.6 m=h=13,996.6\times 0.001 k m\\\\=13.9966 km \approx 14 km$

The maximum height at which nitrogen molecule will go before coming to rest is 14 kilometers.

Learn more about the average kinetic energy of gas particles here:

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6 0

1 year ago

What are the uses of carbon-14?

Gelneren [198K]

Carbon-14 is a radioactive isotope used to date organic material. Its consistent rate of decay allows the age of an object to be determined by the proportion of carbon-14 to other carbon isotopes. This process is called radiocarbon dating. Carbon-14 is also used as a radioactive tracer for medical tests.

6 0

2 years ago

Ions form as a result of uneven charge distribution between the nucleus and the electron cloud. TRUE OR FALSE

storchak [24]

Answer:

true

Explanation:

true

8 0

2 years ago