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3 years ago

In the quantum mechanical model, each allowed ____ has a precisely known energy, but the location of the electron

Chemistry

1 answer:

rusak2 [61]3 years ago

5 0

Answer:

Orbital

Explanation:

In Bohr's model, the planet model, it was thought that electrons were orbiting a nucleus just as planets are orbiting the sun. Over time, this model was proved to be inconsistent with the further findings, especially with the fact that electrons exhibited wave properties.

This lead to defining orbitals in terms of quantum mechanics. An orbital is defined as a space in which the probability of finding an electron is 95 %. Each allowed orbital has a precisely known energy, this is why we can calculate the energy needed to promote an electron to a higher orbital, as we know the difference in energies between the orbitals.

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The term El Nino/Southern Oscillation refers to the occurrence of warmer than normal sea surface temperatures in the Eastern Pac

Amiraneli [1.4K]

Answer:

True

Explanation:

The El Nino/Southern Oscillation occurs in between the three phases Neutral, La Nina or El Nino.

The humboldt current takes cold water to South America's west coast to the tropics from the Southern Ocean. Because of the welling which takes place in Peru this process is enhanced. Due to the trade winds near the equator the cold water travels west where it heats up due to the sun. This makes the water of the western Pacific warmer.

6 0

4 years ago

A chemist mixes 1.00 g CuCl2 with an excess of (NH4)2HPO4 in dilute aqueous solution . He measures the evolution of 670 J of hea

kaheart [24]

Answer:

$\Delta H$ will be 90054 J

Explanation:

Number of moles = (mass)/(molar mass)

Molar mass of $CuCl_{2}$ = 134.45 g/mol

So, 1.00 g of $CuCl_{2}$ = $\frac{1.00}{134.45}mol$ of $CuCl_{2}$ = 0.00744 mol of $CuCl_{2}$

0.00744 mol of $CuCl_{2}$ produces 670 J of heat

So, 1 mol of $CuCl_{2}$ produces $\frac{670}{0.00744}J$ of heat or 90054 J of heat

4 0

4 years ago

Acid rain is an example of _____________ weathering

olga nikolaevna [1]

Answer:

Chemical weathering

Chemical weathering describes the chemicals in rainwater making changes to the minerals in a rock. Carbon dioxide from the air is dissolved in rainwater making it slightly acidic. A reaction can occur when the rainwater comes into contact with minerals in the rock, causing weathering.

6 0

3 years ago

Is crushing a rock a chemical or physical change?

aalyn [17]

Physical change because you didn't change the chemical compound

4 0

3 years ago

An organic acid was analyzed and the following percent composition was obtained: 68.85% carbon, 4.9% hydrogen, and 26.2% oxygen.

rewona [7]

Answer:

The molecular formula of the compound is: C14H12O4

Explanation:

Step 1: find molality

ΔT = Kf x m

ΔT = Tfinal - Tinitial = 3.37 - 5.50 = -2.13

molality (m) = ΔT/Kf = -2.13/-5.12 = 0.416 m

step 2: find number of moles

m = number of moles (n)/Kg solvent which is the benzene

n = molality x Kg solvent = 0.416 molality X (10 x 10^-3 Kg) = 0.00416 mole

Step 3: find molecular mass of the organic compound

n = mass/Molecular mass = m/Mm

Mm = m/n = 1.02/0.00416 = 245.19 g/mole of organic compound molecular formula

Step 4: find number of mole of each compound

let consider it being in 100g where each % will correspond to the mass of the element in 100g of the compound.

C = mass/molar mass = 68.85/12.01 = 5.7327 mole

H = mass/molar mass = 4.9/1.01 = 4.8515 mole

O = mass/molar mass = 26.2/16 = 1.6375 mole

Step 5: divide by smallest number of mole

C = 5.7327/1.6375 = 3.5 = 7/2

H = 4.8515/1.6375 = 3

O = 1.6375/1.6375 = 1

C7/2H3O1

multiply by two to remove the fraction: C7H6O2 in which the empirical molecular mass = 122.13 g/mole

to find the factor for the molecular formula x = Mm of molecular/Mm of empirical = 245.19/122.13 = 2

Multiply the empirical by 2 = 2 x (C7H6O2) = C14H12O4

8 0

4 years ago