All categories

2 years ago

The electron configuration of an element is 1s22s22p¹. How many valence electrons does the element have

Chemistry

1 answer:

Cloud [144]2 years ago

4 0

Answer:

$\huge\boxed{\sf 3 \ electrons}$

Explanation:

<h3>Electronic configuration:</h3>

$1s^22s^22p^1$

The outermost/valence shell is the second one, seeing from the electronic configuration.

<h3>Valence electrons:</h3>

= 2 + 1 = 3 (electrons are raised to the power in the electronic configuration)

Since, the valence shell here is 2, the electrons of second shell will be counted as valence electrons.

$\rule[225]{225}{2}$

You might be interested in

Phosphorus trichloride reacts with chlorine to form phosphorus pentachloride.

zalisa [80]

Answer:

[PCl₃] = [Cl₂] = 0.035M

[PCl₅] = 0.059M

Explanation:

Based on the chemical reaction, Kc is:

Kc = 49 = [PCl₅] / [PCl₃] [Cl₂]

<em>Where [] are the concentrations in equilibrium of each species</em>

<em />

The initial concentration of the reactants is:

[PCl₃] = [Cl₂] = 0.75mol / 8.0L = 0.094M

The reactants must be consumed whereas PCl₅ will be produced. That is:

[PCl₃] = [Cl₂] = 0.094M - X

[PCl₅] = X

<em>Where X is the reaction coordinate</em>

<em />

Replacing in Kc expression:

49 = [X] / [0.094 - X] [0.094 - X]

49 = [X] / 0.008836 - 0.188 X + X²

0.432964 - 9.212 X + 49 X² = X

0.432964 - 10.212 X + 49 X² = 0

Solving for X

X = 0.059M → Right solution

X = 0.15M → False solution. Will produce negative concentrations

Replacing:

[PCl₃] = [Cl₂] = 0.094M - 0.059M = 0.035M

[PCl₅] = 0.059M

5 0

3 years ago

Which example best shows conservation of resources?

Inessa05 [86]

Answer:

Recycling aluminum cans and glass bottles

7 0

3 years ago

Read 2 more answers

A student has two identical glasses of milk except that the temperature of the milk in one glass is 40ºF

kiruha [24]

80ºF.

Explanation:

At a temperature of 80ºF, the milk has the highest thermal energy.

The thermal energy in a body increases as the temperature of the body increases.

To increase the temperature of a body, heat is a supplied to it or work is done on it.

Heat is a form of thermal energy.
As the heat increases, the particles of the milk gains more kinetic energy.
This forces them to move more faster.
A body with a higher temperature has more thermal energy.

Learn more:

Temperature and heat brainly.com/question/914750

#learnwithBrainly

5 0

4 years ago

Using the following thermochemical data: 2Y(s) + 6HF(g) → 2YF3(s) + 3H2(g) ΔH° = –1811.0 kJ/mol 2Y(s) + 6HCl(g) → 2YCl3(s) + 3H2

Luba_88 [7]

Answer:

ΔH° = 182.4 kJ/mol

Explanation:

The ΔH wanted is for the reaction :

YF3(s) + 3HCl(g) → YCl3(s) + 3HF(g)

This is a Hess Law problem where e will have to algebraically manipulate the first and second equations , add them together, and arrive at the desired equation above.

Notice if we reverse the first equation and divide it by 2 and add to the the second only divided by two, we will arrive to the desired equation:

2YF3(s) + 3H2(g) → 2Y(s) + 6HF(g) ΔH° = 1811.0 kJ/mol (change sign)

dividing by two :

YF3(s) + 3/2H2(g) → Y(s) + 3HF(g) ΔH° = 905.5 kJ/mol Eq 1

2Y(s) + 6HCl(g) → 2YCl3(s) + 3H2(g) ΔH° = –1446.2 kJ/mol

dividing this one by two,

Y(s) + 3HCl(g) → YCl3(s) + 3/2 H2(g) ΔH° = –1446.2 kJ/mol/2 = - 723.10 kJ/mol Eq 2

Now adding 1 and 2

YF3(s) + 3/2H2(g) → Y(s) + 3HF(g) ΔH° = 905.5 kJ/mol Eq 1

Y(s) + 3HCl(g) → YCl3(s) + 3/2 H2(g) ΔH° = –1446.2 kJ/mol/2 = - 723.10 kJ/mol Eq 2

________________________________________________________

YF3(s) + 3HCl(g) → YCl3(s) + 3HF(g). ΔH° = 905.5 + (-723.1) kJ/mol

ΔH° = 182.4 kJ/mol

Notice how the Y(s) and H2 cancel nicely and the coefficients are the right ones.

8 0

4 years ago

Biochemical reactions in your cells occur best at approximately which temperature

timama [110]

Answer:

38°c

Explanation:

Biochemical reactions takes place in our body at an approximate temprature of 38°c...

4 0

3 years ago

Read 2 more answers