All categories

4 years ago

How to find valence electrons?

2 answers:

7 0

Find a periodic table of elements. This is a color-coded table made up of many different squares that lists all of the chemical elements known to humankind. The periodic table reveals lots of information about the elements — we'll use some of this information to determine the number of valence electrons in the atom we're investigating. You can usually find these inside the cover of chemistry textbooks. There is also an excellent interactive table available online here.

maks197457 [2]4 years ago

5 0

The valence Electron are the electrons in last electron shell is the valence electrons.

Hope this helps

You might be interested in

Given 6193 mL of a gas at 62.3 °C. What is its volume at 38.1 °C?

Luden [163]

Answer:

5746.0 mL.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and P are constant, and have two different values of V and T:

V₁T₂ = V₂T₁

V₁ = 6193.0 mL, T₁ = 62.3°C + 273 = 335.3 K.

V₂ = ??? mL, T₂ = 38.1°C + 273 = 311.1 K.

∴ V₂ = V₁T₂/T₁ = (6193.0 mL)(311.1 K)/(335.3 K) = 5746.0 mL.

5 0

3 years ago

Unit: Stoichiometry

Reika [66]

Answer:

1. 2.41 × 1023 formula units

2. 122 L

3. 7.81 L

Explanation:

1. Equation of the reaction: 2 Na(NO3) + Ca(CO3) ---> Na2(CO3) + Ca(NO3)2

Mole ratio of NaNO3 to CaCO3 = 2 : 1

Moles of CaCO3 = mass/molar mass

Mass of CaCO3 = 20 g; molar mass of CaCO3 = 100 g

Moles of CaCO3 = 20 g/100 g/mol = 0.2 moles

Moles of NaNO3 = 2 × 0.2 moles = 0.4 moles

1 Mole of NaNO3 = 6.02 × 10²³ formula units

0.4 moles of NaNO3 = 0.4 × 6.02 × 10²³ = 2.41 × 1023 formula units

2. Equation of reaction : 2 H2O ----> 2 H2 + O2

Mole ratio of oxygen to water = 1 : 2

At STP contains 6.02 × 10²³ molecules = 1 mole of water

6.58 × 10²⁴ molecules = 6.58 × 10²⁴ molecules × 1 mole of water/ 6.02 × 10²³ molecules = 10.93 moles of water

Moles of oxygen gas produced = 10.93÷2 = 5.465 moles of oxygen gas

At STP, 1 mole of oxygen gas = 22.4 L

5.465 moles of oxygen gas = 5.465 moles × 22.4 L/1 mole = 122 L

3.Equation of reaction: 6 K + N2 ----> 2 K3N

Mole ratio of Nitrogen gas and potassium = 6 : 1

Moles potassium = mass/ molar mass

Mass of potassium = 90.0 g, molar mass of potassium = 39.0 g/mol

Moles of potassium = 90.0 g / 39.0 g/mol = 2.3077moles

Moles of Nitrogen gas = 2.3077 moles / 6 = 0.3846 moles

At STP, 1 mole of nitrogen gas = 22.4 L

0.3486 moles of oxygen gas = 0.3486 moles × 22.4 L/1 mole = 7.81 L

7 0

3 years ago

Black fur (B) in guinea pigs is domiant over white fur (b).find the probability of a white offspring in a cross between rwo hete

viva [34]

Answer:

50% white offspring

Explanation:

Please friend me if this helped (:

3 0

3 years ago

What are the acceptable solution to the Schrodinger wave equation

alex41 [277]

Answer:

The wave function Ψ(x, t) = Aei(kx−ωt) represents a valid solution to the Schrödinger equation. The wave function is referred to as the free wave function as it represents a particle experiencing zero net force (constant V )

7 0

2 years ago

Given the reaction for the corrosion of aluminum: 4 Al + 3 O2 --> 2 Al2O3, which half-reaction correctly represents the oxida

Pavel [41]

Answer:

Option B, Al --> Al3+ + 3e-

Explanation:

Oxidation is defined as the process of losing electron by a molecule, atom or anion thereby acquiring oxidation state i.e the positive charge. Reduction on the other hand is the process in which an atom, ion or molecule gains electron and gains negative charge on it.

For example – In the reaction, H2 + F2 → 2 HF, hydrogen is oxidized H2 → 2 H+ + 2 e- as it looses electron while fluorine is being reduced F2 + 2 e- → 2 F-

This is happening in the option B

5 0

3 years ago