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3 years ago

I need the 3 questions !!! About Rubidium (Rb) ASAP PLEASE DUE IN LIKE 20 min

Chemistry

1 answer:

hjlf3 years ago

5 0

Answer:

419kJ/mol
5,0,0,+12
That catches fire spontaneously

Explanation:

1. Topic: Chemistry

ElementFirst Ionization Energy (kJ/mol) Lithium520Sodium496Rubidium403Cesium376According to the above table, which is most likely to be the first ionization energy for potassium?

536kJ/mol

504kJ/mol

419kJ/mol

391kJ/mol

358kJ/mol

2. Topic: Chemistry, Atom

The correct set of four quantum numbers for the valence electrons of the rubidium atom (Z=37) is:

5,1,1,+12

5,0,1,+12

5,0,0,+12

5,1,0,+12

3. Rubidium and cesium are pyrophoric. Here the term pyrophoric means:

That hardly catches fire

That does not catch fire at all

That catches fire spontaneously

None of these

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What is the difference between a plain and a plateau? A. Only a plain is flat, a plateau is steep mountainside. B. Both are flat

Alenkinab [10]

Answer:

Explanation:

<em>Both plain and plateau have flat surfaces. However, a plain is located in a low-lying area while a plateau is located on an elevated area. In essence, a plateau can be viewed as an elevated plain or a plain that is bordered by cliffs.</em>

The correct option is B.

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2 years ago

Which compound in the picture has a central atom with four outside atoms and has at least one nonpolar bond.

hodyreva [135]

Answer:

The answer is:

Explanation:

The compound in Option B is Methane.

Methane is known to be a compound which has two elements, carbon and hydrogen. It has a central atom which is surrounded by four hydrogen atoms. It's chemical formula is CH4.

Methane's outer atoms are dipoles and are in the same direction. This makes the overall molecule non-polar. The compound itself has non-polar bonds and it is non-polar itself.

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3 years ago

Describe the type of force which exists between particles in an Ideal gas. Explain why this type of force exists between the par

aksik [14]

The Intermolecular force is a type of force which exists between particles in an Ideal gas.

<h3>What type of force which exists between particles in an Ideal gas?</h3>

Intermolecular forces are considered weaker attractions that hold molecules in gas close together. This force of attraction is present between molecules or particles.

So we can conclude that the Intermolecular force is a type of force which exists between particles in an Ideal gas.

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8 0

1 year ago

A Silty Clay (CL) sample was extruded from a 6-inch long tube with a diameter of 2.83 inches and weighed 1.71 lbs. (a) Calculate

inna [77]

Answer:

a) the wet density of the CL sample is 0.0453 lb/in³

b) the water content in the sample is 65.37%

c) the dry density of the CL sample is 0.0274 lb/in³

Explanation:

Given that;

diameter d = 2.83 in

length L = 6 in

weight m = 1.71 lbs

A piece of clay sample had wet-weight of 140.9 grams and dry-weight of 85.2 grams

a) wet density of the CL sample

wet density can be expressed as p = M /v

V is volume of sample which is; π/4×d²×L

so p = M / π/4×d²×L

we substitute

p = 1.71 / (π/4 × (2.83)²× 6

p = 1.71 / 37.741

p = 0.0453 lbs/in³

so the wet density of the CL sample is 0.0453 lb/in³

water content of sample is taken as;

w = (wet_weight - dry_weight) / dry_weight

we substitute

w = (140.9 - 85.2) / 85.2

w = 55.7 / 85.2

w = 0.6537 = 65.37%

therefore the water content in the sample is 65.37%

dry density of the CL sample

to determine the dry density, we say;

Sd = p / ( 1 + w )

we substitute

Sd = 0.0453 / ( 1 + 0.6537)

Sd = 0.0453 / 1.6537

Sd = 0.0274 lb/in³

therefore the dry density of the CL sample is 0.0274 lb/in³

8 0

3 years ago

Which of these half-reactions represents reduction?

gogolik [260]

Answer: The half-reactions represents reduction are as follows.

$Cr_{2}O^{2-}_{7} \rightarrow Cr^{3+}$
$MnO^{-}_{4} \rightarrow Mn^{2+}$

Explanation:

A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element takes place is called reduction-half reaction.

For example, the oxidation state of Cr in $Cr_{2}O^{2-}_{7}$ is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.

$Cr_{2}O^{2-}_{7} + 3 e^{-} \rightarrow Cr^{3+}$

Similarly, oxidation state of Mn in $MnO^{-}_{4}$ is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.

$MnO^{2-}_{4} + 5 e^{-} \rightarrow Mn^{2+}$

Thus, we can conclude that half-reactions represents reduction are as follows.

$Cr_{2}O^{2-}_{7} \rightarrow Cr^{3+}$
$MnO^{-}_{4} \rightarrow Mn^{2+}$

3 0

2 years ago