Mole are in 5.1 grams of beryllium ?

A sample of a uranium compound is found to be losing mass gradually. Explain what is happening to the sample.

irina [24]

Explanation:

Uranium have an unstable nuclei , hence it is a radioactive element , and radioactive element can undergo radioactive decay like the alpha decay , beta decay .

Radioactive decay is a spontaneous breakdown of the atomic nucleus which , results in the release of energy along with radioactive particles , like alpha , beta , gamma etc .

Hence ,

The mass is lost from a sample of uranium .

3 0

3 years ago

The chemical equation is Mg(s) + O2(g) → MgO(s)

vredina [299]

Answer:

The magnesium will burn until consumed entirely. There is much more oxygen available in the atmosphere than needed to consume the magnesium. Thus the magnesium is the limiting reactant because it determines the amount of product formed.

Explanation:

Mg produces less amount of MgO than O2; therefore Mg is the limiting reagent. O2 produces more amount of MgO than Mg; therefore O2 is the excess reagent.

4 0

3 years ago

The line of longitude used as the origin in a system of coordinates

3241004551 [841]

Yup, that is correct.

7 0

3 years ago

a sample of solid is decomposed and found to contain 6.52g of potassium, 4.34 g of chromium and 5.34 of oxygen, what is the empi

Fynjy0 [20]

Answer:

K₂CrO₅

Explanation:

The empirical formula is the simplest formula of a compound. To find the empirical formula, we follow the procedure below:

Elements Potassium Chromium Oxygen

Mass 6.52 4.34 5.34

Molar mass 39 60 16

Number of moles 6.52/39 4.34/60 5.34/16

0.167 0.072 0.333

Divide through by

the smallest 0.167/0.072 0.072/0.072 0.333/0.072

2.3 1 4.6

2 1 5

Empirical formula K₂CrO₅

5 0

3 years ago

What is the lower concentration limit (vol%) at which a mixture of ethanol in air can explode?

liubo4ka [24]

Answer:

Lower explosive limit (LEL) of ethanol = 3.3%

Explanation:

In the case of alcohol, ethanol presents certain fire hazards. Its momentary flash point is 55ºF (12.9ºC), while the momentary flash point of gasoline is -45ºF (-42.8ºC), and the E85 mixture ranges between -20ºF and -4ºF (between -28 , 9ºC and -20ºC), and has a wider range of flammability limits than gasoline. For emergency response teams, this implies that during a release of the typical ethanol / gasoline mixture, the fuel can be expected to behave like gasoline: It is heavier than air - as we mentioned earlier - and can produce vapors and form flammable mixtures in the air, under most environmental conditions.

General properties and comparison with other inflambles products:

Flash point momentary Gasoline = -45 ° F

<u>Ethanol</u> = 55 ° F

E 85 = between -20º and -4º F

<u>Flammability limits </u>

Lower explosive limit (LEL) of ethanol = 3.3%

Upper Explosive Limit (UEL) = 19%

Lower explosive limit (LEL) of the mixture E 85 = 1.4%

Upper Explosive Limit (UEL) 85 = 19%

Lower explosive limit (LEL) of gasoline = 1.4%

Upper Explosive Limit (UEL) = 7.6%

They have a wider range than gasoline

4 0

3 years ago