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3 years ago

The Valence Electrons of an Atom of Which Element would feel a Greater Effective Nuclear Charge than the Valence?

1 answer:

5 0

The effective nuclear charge is an innate property of a specific element. It is the pull of force that an electron feels from the nucleus. It is related to the valence electron by the equation: Z* = Z-S, where Z* is the effective nuclear charge, Z is the atomic number and S is the shielding constant.

For the following elements in the choices, these are their values of Z*:

Aluminum - +12.591
Beryllium - +1.912
Hydrogen - +1
Carbon - +4

The effective nuclear charge of Boron is +3. Thus, the answers are Aluminum and Carbon.

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The smaller radius is primarily a result of the magnesium atom having ??

Aleksandr [31]

Answer:

A larger nuclear charge :)

Explanation:

8 0

3 years ago

Can any of you guys help me with this. Can y’all give me some facts about nucleus protons netrons and electrons :)

Mumz [18]

Answer:

the nucleus is the center of the atom, made up of protons and neutrons, without the nucleus you'd just have a bunch of electrons floating around; the nucleus is positively charged

protons are the positively charged particles that sit within the nucleus

neutrons are particles of no charge that sit within the nucleus, and because they have no charge, they do not cancel out the positive charge of the protons, making the nucleus positive

electrons are negatively charged particles that float around the nucleus in an area known as the electron cloud, they orbit around the nucleus because they are attracted to the positive charge of the nucleus (caused by the protons), with charges, opposites attract

Explanation:

4 0

3 years ago

A buffer consists of 0.45 M CH3COOH (acetic acid) and 0.35 M CH3COONa. The Ka of acetic acid is 1.8 x 10-5 . a) Calculate the pH

Zigmanuir [339]

Answer:

A) pH of Buffer solution = 4.59

B) pH after 5.0 ml of 2.0 M NaOH have been added to 400 ml of the original buffer solution = 4.65

Explanation:

This is the Henderson-Hasselbalch Equation:

$pH = pKa + log\frac{[conjugate base]}{[acid]}$

to calculate the pH of the following Buffer solutions.

8 0

3 years ago

How much mass defect is required to release 5.5 x 1020 J of energy?

Montano1993 [528]

Answer : The mass defect required to release energy is 6111.111 kg

Explanation :

To calculate the mass defect for given energy released, we use Einstein's equation:

$E=\Delta mc^2$

E = Energy released = $5.5\times 10^{20}J$

$\Delta m$ = mass change = ?

c = speed of light = $3\times 10^8m/s$

Now put all the given values in above equation, we get:

$5.5\times 10^{20}Kgm^2/s^2=\Delta m\times (3\times 10^8m/s)^2$

$\Delta m=6111.111kg$

Therefore, the mass defect required to release energy is 6111.111 kg

5 0

3 years ago

You are requested to reduce the size of 50 ton/hr of a given solid. The size of the feed is such 80% passes a 4-in (76.2 mm) scr

defon

Answer:

1) The power needed to process 50 ton/hr is 135.4 HP.

2) The void fraction of the bed is 0.37.

Explanation:

1) For this type of milling operations, we can estimate the power needed for an operation according to the work index (Ei), the passing size of the circuit feed (F80) and the passing size of the product (P80).

We assume the units of Ei are kWh/t.

The equation that relates this parameters and the power is (size of particles in μm):

$W=Ei*(\frac{10}{\sqrt{P80}} -\frac{10}{\sqrt{F80}} )\\\\W=9.45*(\frac{10}{\sqrt{3175\mu m}} -\frac{10}{\sqrt{76200mm}} )\\\\\\W=9.45*(0.1774+0.0362)=2.019 kWh/t$

The power needed to process 50 ton/hor is

$P=2.0194\frac{kWh}{Ton}*\frac{50Ton}{h}*\frac{1.341HP}{1kW}= 135.4 \, HP$

2) The density of the packed bed can be expressed as

$\rho=f_v*\rho_v+f_s*\rho_s$

being f the fraction and ρ the density of every fraction. We know that the density of the void is 0 (ρv=0) and that fv=1-fs (the sum of the fractions ois equal to the total space).

Then we can rearrange

$\rho=f_v*\rho_v+f_s*\rho_s\\\\\rho=f_v*0+(1-f_v)*\rho_s\\\\\rho/\rho_s=1-f_v\\\\f_v=1-\rho/\rho_s=1-990/1570=1-0.63=0.37$

The void fraction of the bed is 0.37.

6 0

3 years ago