Which example best describes a reflex action?

The ionization energies of rubidium and silver are 4.18 and 7.57 eV, respectively. Calculate the ionization energies of an H ato

Artist 52 [7]

Answer:

0.544 eV; Ag is a smaller atom.

Explanation:

1. Ionization energy of hydrogen

The outermost electrons in Rb and Ag are in 5s orbitals.

The formula for the energy of an electron in a hydrogen atom is

E = -13.6/n² eV

For a hydrogen atom in a 5s orbital,

E = -13.6/5² = -13.6/25 = -0.544 eV

The ionization energy would be 0.544 eV.

2. Rb vs Ag

The first electrons to be removed from Rb and Ag are in 5s orbitals.

The atomic radius of Ag is less than that of Rb because, as you go from left to right across the Row, you are adding 10 protons to the nucleus and 10 electrons to the outer shell.

The added electrons do not effectively shield each other from the attraction of the nucleus, so the 5s electron of Ag is closer in.

It takes more energy to remove the electron from silver, so the ionization energy of Ag is greater than that of Rb.

4 0

3 years ago

What is the importance of dissolved co2 and o2 in water

hodyreva [135]

Answer:

The oxygen O2, and the carbon dioxide (CO2) dissolved in water are very important to keep live in aquatic bodies.

Explanation:

Oxygen (O2) is an element found in nature usually as a gas in the air that we breathe. Oxygen is very important for aerobic organisms, including us, the humans. It can dissolve in water, and it is vital for the health of aquatic habitats. If we have low quantity of oxygen dissolve in water means that could be a pollution problem. Actually the oxygen level is an indicator to determine the water quality. In order to survive the aquatic biota (animals and plants) need certain quantity of oxygen. The oxygen dissolved in the water comes from the air, because of the wind, rain, waves, currents, and from aquatic plants like algae thanks to a process call photosynthesis.

Carbon Dioxide (CO2) is a chemical compound. This gas also is found in the air, and can be dissolved in water easier than oxygen. Aquatic plants needs CO2, to produce their own food during the photosynthesis process. It´s very important to have enough CO2, for the growth of aquatic plants. But if we have to much CO2 the fish will not have enough oxygen and could suffocate and die. Aquatic animals through respiration process produce CO2, it also can be obtained from fermentation, and from the burning of any substance that has carbon C.

If we want to preserve live in the aquatic bodies we must keep the balance between oxygen and carbon dioxide.

4 0

3 years ago

A 25.00 ml solution of sulfuric acid H2SO4 is titrated to phenolphthalein end point with 27.00 ml of 1.700 M KOH

Nastasia [14]

<h3>Answer:</h3>

0.918 M

<h3>Explanation:</h3>

Assuming the question requires we calculate the Molarity of sulfuric acid:

We are given:

Volume of the acid, H₂SO₄ = 25.00 ml
Volume of the base, KOH = 27.00 mL
Molarity of the base, KOH is 1.70 M

We can calculate the molarity of the acid using the following steps;

<h3>Step 1: Write the chemical equation for the reaction.</h3>

The reaction is an example of a neutralization reaction where a base reacts with an acid to form salt and water.

Therefore, the balanced equation will be;

H₂SO₄(aq) + 2KOH(aq) → K₂SO₄(aq) + 2H₂O(l)

<h3>Step 2: Determine the moles of the base, KOH </h3>

When given molarity and the volume of a solution, the number of moles can be calculated by multiplying molarity with volume.

Number of moles = Molarity × Volume

= 1.700 M × 0.027 L

= 0.0459 moles

Thus, moles of KOH used is 0.0459 moles

<h3>Step 3: Determine the number of moles of the Acid, H₂SO₄</h3>

From the reaction, 1 mole of the acid reacts with 2 moles of KOH

Therefore, the mole ratio of H₂SO₄ to KOH is 1 : 2

Thus, moles of H₂SO₄ = Moles of KOH ÷ 2

= 0.0459 moles ÷ 2

= 0.02295 moles

<h3>Step 4: Calculate the molarity of the Acid </h3>

Molarity is the concentration of a solution in moles per liter

Molarity = Moles ÷ Volume

Molarity of the acid = 0.02295 moles ÷ 0.025 L

= 0.918 M

Thus, the molarity of the acid, H₂SO₄ is 0.918 M

5 0

3 years ago

Wat are the five assumption of kinetic therory of gases

il63 [147K]

Answer:

The five assumption of Kinetic molecular theory are given below.

Explanation:

Kinetic molecular theory of gasses stated that,

1) Gases consist of large number of smaller particles which are distance apart from each others.

2) The gas molecules collide with each other and also with wall of container and this collision is elastic.

3) Gas molecules are in continuous random motion and posses kinetic energy.

4) The forces of attraction between gas molecules are very small and considered negligible.

5) The temperature of gas is directly proportional to average kinetic energy of gas molecules.

6 0

3 years ago

O que são processos físicos de separação das misturas? Dê 3 exemplos

chubhunter [2.5K]

Answer:

Explanation:

The physical methods of separating mixtures are used in sorting a mixture of substances.

It requires no chemical changes occurring between their components and parts in any significant way.

Examples are:

Decantation
Filtration
Sublimation
Magnetism
Centrifugation

The methods simply relies on the physical properties of matter.

8 0

3 years ago