All categories

3 years ago

In atomic science, the z number refers to the number of __________ in the nucleus of an atom.

1 answer:

6 0

By convention, the symbol Z is assigned to the number of protons in the nucleus, or simply, the atomic number of an element. This is actually used when you want to determine the effective nuclear charge of a specific electron of an element. The equation is:

Z* = Z - S
where
Z* is the effective nuclear charge
Z is the atomic number
S is the number of electrons between the electron in question and the nucleus

There is due to a phenomenon called the shielding effect. This effect states that the farther the electron is from the nucleus, the lesser is its pull of force to the nucleus. That is the reason why the valence electrons (outermost electrons) are the ones always involved in chemicals reactions. Because they are not that strongly bonded to the nucleus of an atom.

You might be interested in

Hydrogen produced from a hydrolysis reaction was collected over water and the following data was compiled.

Shkiper50 [21]

Answer:

0.00358 mol

Explanation:

1) Data:

a) V = 93.90 ml

b) T = 28°C

c) P₁ = 744 mmHg

d) P₂ = 28.25 mmHg

d) n = ?

2) Conversion of units

a) V = 93.90 ml × 1.000 liter / 1,000 ml = 0.09390 liter

b) T = 28°C = 28 + 273.15 K = 301.15 K

c) P₁ = 744 mmHg × 1 atm / 760 mmHg = 0.9789 atm

d) P₂ = 28.5 mmHg × 1 atm / 760 mmHg = 0.0375 atm

3) Chemical principles and formulae

a) The total pressure of a mixture of gases is equal to the sum of the partial pressures of each gas. Hence, the partical pressure of the hydrogen gas collected is equal to the total pressure less the vapor pressure of water.

b) Ideal gas equation: pV = nRT

4) Solution:

a) Partial pressure of hydrogen gas: 0.9789 atm - 0.0375 atm = 0.9414 atm

b) Moles of hygrogen gas:

pV = nRT ⇒ n = pV / (RT) =

n = (0.9414 atm × 0.09390 liter) / (0.0821 atm-liter /K-mol × 301.15K) =

n = 0.00358 mol (which is rounded to 3 significant figures) ← answer

7 0

3 years ago

Read 2 more answers

Which of the following could be the subsh

andreev551 [17]

Answer:

$2s^2 2p^2$

Explanation:

Group 4A contains a total of 4 electrons for each atom in their valence shell. Filling the orbital diagram, let's say, for carbon, notice that when we start with period 2, we have two elements in the s-block, that is, lithium and beryllium. They correspond to the two s electrons that belong to the valence shell of carbon.

Moving on, we have boron and carbon, the remaining 2 electrons. Now, starting with boron, we're in the p-block.

That said, looking at the second period, the electron configuration for the valence shell of a group 4A element would be:

$2s^2 2p^2$

6 0

3 years ago

What does it mean to have protein in your urine?

konstantin123 [22]

It is often a sign of kidney problems. :)

6 0

3 years ago

Which isomer of 1-bromo-4-tert-butylcyclohexane reacts faster when refluxed with potassium tert-butoxide?

grigory [225]

Answer:

See explanation.

Explanation:

Since potassium tert-butoxide is a strong bulky base, we expect that an elimination reaction predominates.

This reaction is expected to occur by E2 mechanism. The cis isomer of 1-bromo-4-tert-butylcyclohexane is known to react faster by E2 mechanism because it fulfills the anticoplanar arrangement required for for E2 mechanism, where the leaving group and adjacent proton must be anti to each other and in the same plane. The trans isomer can not fulfill this requirement.

7 0

3 years ago

In a chemical reaction, water decomposes to form hydrogen and oxygen. What is the correct term for the water?

gulaghasi [49]

The answer is: [D]: a reactant.
________________________

7 0

3 years ago

Read 2 more answers