Answer:
d) Cr⁺³
Explanation:
Consideremos un ion que contiene 24 protones, 28 neutrones y 21 electrones.
Para encontrar el simbolo del elemento, tenemos que considerar el número atómico (Z) que es igual al número de protones. Con esta información, buscamos en la tabla periódica el elemento con Z=24 es el Cromo.
La carga total está dada por la diferencia entre protones y electrones. Los ´protones tienen carga +1 y los electrones carga -1. Luego, este ion tiene carga:
24 protones + 21 electrones = 24 . (1) + 21 . (-1) = +3
El simbolo del ion es Cr⁺³.
Principle quantum number describes the energy of an electron and most probable distance of the electron from the nucleus.
<h3>What is the significance of principle quantum numbers and azimuthal quantum numbers?</h3>
A principal quantum number signifies size and energy of the orbital.Azimuthal quantum number signifies three dimensional shape of the orbital.
Magnetic quantum numbers signifies spatial orientation of the orbital.
Principal quantum numbers is the quantum numbers denoted by n which indirectly describes the size of the electron orbitals. It is always assigned an integer value but its value never be 0. The feature of a principal quantum numbers is the energy of an electron and most probable distance of the electron from the nucles.
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Answer:
The answer to your question is 8.74 g of He
Explanation:
Data
V = 2.4 x 10² L
P = 99 kPa
T = 0°C
mass = ?
Process
1.- Convert kPa to atm
P = 99 kPa = 99000 Pa
1 atm --------------- 101325 Pa
x --------------- 99000 Pa
x = (99000 x 1) / 101325
x = 0.977 atm
2.- Convert temperature to °K
°K = 273 + 0
°K = 273
3.- Substitution
PV = nRT
- Solve for n
n = PV / RT
n = (0.977)(2.4 x 10²) / (0.082)(273)
n = 24.48 / 22.386
n = 1.093 moles
4.- Calculate the grams of He
8 g -------------------- 1 mol
x -------------------- 1.093 moles
x = (1.093 x 8) / 1
x = 8.74 g
<span><em>Answer:</em>
A strontium-90 atom that has a lost two electrons has <u>38</u> protons, <u>52</u> neutrons, and <u>36</u> electrons.
<em>Explanation:
</em>Atomic number<em> of </em>Strontium (Sr) is 38.
<em>Atomic number = number of protons
</em>Hence, Strontium has 38 protons.
If the element is in neutral state,
number of protons = number of electrons.
Then, neutral Strontium atom should have 38 electrons.
But the question says Sr has lost 2 electrons. Hence, number of electrons should be 38 - 2 = 36.
Mass number = number of protons + number of neutrons.
The given mass number is 90. Hence, number of neutrons should be 90 - 38 = 52.</span>
