All categories

3 years ago

What is the atomic mass of helium?

1 answer:

8 0

4.002602 u
Being one of the lightest elements in the world, Helium has an atomic mass of 4.0026 u. u means Unified Atomic Mass Units. 1 u equals to the mass of 1/12 of the mass of a 12C ( Carbon - 12 ) isotope.

You might be interested in

Which of the following is a double replacement reaction?

Gekata [30.6K]

Answer:

The answer to your question is: letter D.

Explanation:

Double replacement reaction is when the cation of one reactant replaces the metal of the other reactant and vice versa.

a. 2SO2 + O2 —> 2S03 This is a combination reaction

b. Zn + Cu(NO3)2 → Zn(NO3)2 + Cu This is a single replacement reaction.

c. 2H2O2–> 2H2O + O2 This is a decomposition reaction

d . AgNO3 + NaCl → AgCl + NaNO3 This is a double replacement reaction

7 0

3 years ago

an electron travels in a vacuum tube that is 2 meters in length .002 seconds what is the average speed of the electron during th

9966 [12]

They run about 45.9 miles per hour

6 0

3 years ago

Read 2 more answers

A 975 L balloon contains helium. On the ground the temperature is 30 0C and the pressure is 743 torr. What will be the balloon's

Archy [21]

Answer:

V₂ = 1518L

Explanation:

-Using combined gas law:

$\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}$

<em>Where P is pressure, V is volume and T is absolute temperature of 1, initial state and 2, final state of the gas.</em>

<em />

<em>Initial states:</em>

P₁ = 743 torr

V₁ = 975L

T₁ = 30°C + 273.15K = 303.15K

P₂ = 375 mmHg = torr

V₂ = Our incognite

T₂ = -35°C + 273.15K = 238.15K

Replacing:

$\frac{743torr*975L}{303.15K} =\frac{375torrV_2}{238.15K}$

6 0

3 years ago

What makes venison (meat from deer) a renewable resource?

pshichka [43]

Answer:

Explanation:

Its renewable because of the reproduction and the are born every spring

6 0

3 years ago

Read 2 more answers

What is the equilibrium partial pressure of water vapor above a mixture of 62.9 g H2O and 33.2 g HOCH2CH2OH at 55 °C. The partia

bija089 [108]

Answer : The partial pressure of $H_2O$ is 102.3 mmHg.

Explanation :

As per question,

Mass of $H_2O$ = 62.9 g

Mass of $HOCH_2CH_2OH$ = 33.2 g

Molar mass of $H_2O$ = 18 g/mole

Molar mass of $HOCH_2CH_2OH$ = 62 g/mole

First we have to calculate the moles of $H_2O$ and $HOCH_2CH_2OH$ .

$\text{Moles of }H_2O=\frac{\text{Mass of }H_2O}{\text{Molar mass of }H_2O}=\frac{62.9g}{18g/mole}=3.49mole$

$\text{Moles of }HOCH_2CH_2OH=\frac{\text{Mass of }HOCH_2CH_2OH}{\text{Molar mass of }HOCH_2CH_2OH}=\frac{33.2g}{62g/mole}=0.536mole$

Now we have to calculate the mole fraction of $H_2O$ and $HOCH_2CH_2OH$ .

$\text{Mole fraction of }H_2O=\frac{\text{Moles of }H_2O}{\text{Moles of }H_2O+\text{Moles of }HOCH_2CH_2OH}=\frac{3.49}{3.49+0.536}=0.867$

$\text{Mole fraction of }HOCH_2CH_2OH=\frac{\text{Moles of }HOCH_2CH_2OH}{\text{Moles of }H_2O+\text{Moles of }HOCH_2CH_2OH}=\frac{0.536}{3.49+0.536}=0.134$