238 U 92 is an isotope notation. what is the atomic number, mass number, number of protons, and number of neutrons?

What element has the electron configuration 1s2 2s2 2p6 3s2 3p1?

Westkost [7]

1s2 2s2 2p6 3s2 3p1 is the electron configuration of Aluminum, written as Al.

3 0

3 years ago

Which of the following is not correctly paired with its dominant type of intermolecular forces? 1. SiH4, instantaneous dipoles 2

Luda [366]

Answer:

Option 4. There's no hydrogen bonding between HBr molecules at all.

Explanation:

SiH₄ molecules are tetrahedral and symmetric. Dipoles due to the polar Si-H bonds balance each other. SiH₄ molecules are nonpolar. Only instantaneous dipoles are possible between those molecules.

<h3>C₆H₆ Benzene</h3>

Similar to SiH₄, benzene is symmetric. Dipoles due to the weakly polar C-H bonds balance each other. Benzene molecules are nonpolar. Only instantaneous dipoles are possible between those molecules.

There are two conditions for hydrogen bonding to take place:

H atoms are directly bonded to a highly electronegative element: Nitrogen, Oxygen, or Fluorine.
There is at least one lone pair of electrons nearby.

Consider the Lewis structure of NH₃. There are three H atoms in each NH₃ molecule. Each of the three H atoms is bonded directly to the N atom with a highly polar N-H bond. Also, there is a lone pair of electrons on the N atom. Hydrogen bonding will take place between NH₃ molecules.

NH₃ is a relatively small molecule. As a result, hydrogen bonding will be the dominant type of intermolecular force between NH₃ molecules.

There are three lone pairs on the Br atom in each HBr molecule. However, no H atom is connected to any one of the three highly electronegative elements: N, O, or F. The Br atom isn't electronegative enough for the H atom to form hydrogen bonding. HBr molecules are polar. As a result, the dominant type of intermolecular forces between HBr molecules will be dipole-dipole interactions (A.k.a. permanent dipole.)

Calcium is a group 2 metal. Oxygen is one of the three most electronegative nonmetal. (Again, the most electronegative elements are: Nitrogen, Oxygen, and Fluorine.) As a main group metal, Ca atoms tend to lose electrons and form positive ions. Oxygen will gain those electrons to form a negative ion. As a result, CaO will be an ionic compound full of Ca²⁺ and O²⁻ ions. Forces between ions with opposite charges are called ionic bonds.

7 0

3 years ago

URGENT WILL GIVE BRAINLEIST In two or more complete sentences explain how to balance the chemical equation,

Pani-rosa [81]

Answer:

you add the atoms together

Explanation:

3 0

3 years ago

Read 2 more answers

Define ionization energy and explain why the second ionization energy of any element is higher than its first ionization energy.

pochemuha

The amount of energy required to remove the most loosely bound electron in1 mole of an atom in its neutral gaseous state. Atomic radius is smaller, great nuclear charge (pulling power of protons on less electrons)

7 0

3 years ago

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A silver cube with an edge length of 2.38 cm and a gold cube with an edge length of 2.79 cm are both heated to 81.9 ∘C and place

never [62]

Answer:

The final temperature of the water when thermal equilibrium is reached is 23.54 ⁰C

Explanation:

<u>Given data;</u>

edge length of silver, a = 2.38 cm = 0.0238 m

edge length of gold, a = 2.79 cm = 0.0279 m

final temperature of silver, t = 81.9 ° C

final temperature of Gold, t = 81.9 ° C

initial temperature of water, t = 19.6 ° C

volume of water, v = 109.5 mL = 0.0001095 m³

<u>Known data:</u>

density gold 19300 kg/m³

density silver 10490 kg/m³

density water 1000 kg/m³

specific heat gold is 129 J/kgC

specific heat silver is 240 J/kgC

specific heat water is 4200 J/kgC

<u>Calculated data</u>

Apply Pythagoras theorem to determine the side of each cube;

Silver cube;

let L be the side of the silver cube

Taking the cross section of the cube (form a right angled triangle), the edge length forms the <em>hypotenuse side</em>.

L² + L² = 0.0238²

2L² = 0.0238²

L² = 0.0238² / 2

L² = 0.00028322

L = √0.00028322

L = 0.0168

Volume of cube = L³

Volume of the silver cube = (0.0168)³ = 4.742 x 10⁻⁶ m³

Gold cube;

let L be the side of the gold cube

L² + L² = 0.0279²

2L² = 0.0279²

L² = 0.0279² / 2

L² = 0.0003892

L = √0.0003892

L = 0.0197

Volume of cube = L³

Volume of the silver cube = (0.0197)³ = 7.645 x 10⁻⁶ m³

Mass of silver cube;

density = mass / volume

mass = density x volume

mass of silver cube = 10490 (kg/m³) x 4.742 x 10⁻⁶ (m³) = 0.0497 kg

Mass of Gold cube

mass of gold cube = 19300 (kg/m³) x 7.645 x 10⁻⁶ (m³) = 0.148 kg

Mass of water

mass of water = 1000 (kg/m³) x 0.0001095 (m³) = 0.1095 kg

Let the heat gained by cold water be Q₁

Let the heat lost by silver cube = Q₂

Let the heat lost by gold cube = Q₃

Let the final temperature of water = T

Q₁ = 0.1095 kg x 4200 J/kgC x (T–19.6)

Q₂ = 0.0497 kg x 240 J/kgC x (81.9–T)

Q₃ = 0.148 kg x 129 J/kgC x (81.9–T)

At thermal equilibrium;

Q₁ = Q₂ + Q₃

0.1095 x 4200 (T–19.6) = 0.0497 x 240 x (81.9–T) + 0.148 x 129 x (81.9–T)

459.9 (T–19.6) = 11.928 (81.9–T) + 19.092(81.9–T)

459.9T - 9014.04 = 976.9032 - 11.928T + 1563.6348 - 19.092T

459.9T + 11.928T + 19.092T = 9014.04 + 976.9032 + 1563.6348

490.92T = 11554.578

T = 11554.578 / 490.92

T = 23.54 ⁰C

Therefore, the final temperature of the water when thermal equilibrium is reached is 23.54 ⁰C

6 0

3 years ago