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3 years ago

How many valence electrons are represented in the following electron configuration? 1s22s22p5

1 answer:

Alex3 years ago

7 0

Answer is: d) 7.
Electron configuration: 1s²2s²2p⁵.
Valence electrons are in 2s and 2p orbitals.
Valence electrons are outer shell electrons (transition metal can have a valence electrons in an inner shell) that is associated with an atom and they can form chemical bond. Valence eletrons determine chemical proporties of element.

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Is Mg a metal non metal or noble gas

madam [21]

It is a metal
hope it helps

8 0

3 years ago

At room temperature (20°C} and pressure, the density of air is 1.189 g/L. An object will float in air if its density is less tha

Alekssandra [29.7K]

Explanation:

$Density =\frac{Mass}[Volume}$

Density of the air ,d= 1.189 g/L

(a) Density of the evacuated ball

Mass of the ball ,m = 0.12 g

Volume of the ball = $V=560 cm^3=560 ml=0.560 L$

$D =\frac{0.12 g}{0.560 L}=0.214 g/L$

D<d, teh evacuated ball will flaot in air.

(b) Density of the evacuated ball D = 0.214 g/L

Density of carbon dioxide gas = $d_1=1.830 g/L$

Mass of the carbon dioxide gas :

$1.830 g/L\times 0.560 L=1.0248 g$

Total density of filled ball with carbon dioxide gas:

$\frac{0.12 g+1.0248 g}{0.560 L}==2.044 g/L$

The ball filled with carbon dioxide will not float in the air because total density of filled ball is greater than the density of an air.

(c) Density of the evacuated ball D = 0.214 g/L

Density of hydrogen gas = $d_2=0.0899 g/L$

Mass of the hydrogen gas :

$1.830 g/L\times 0.560 L=0.050344 g$

Total density of filled ball with hydrogen gas:

$\frac{0.12 g+0.050344 g}{0.560 L}==0.3041 g/L$

The ball filled with hydrogen will float in the air because total density of filled ball is lessor than the density of an air.

(d) Density of the evacuated ball D = 0.214 g/L

Density of oxygen gas = $d_3=1.330 g/L$

Mass of the oxygen gas :

$1.330 g/L\times 0.560 L=1.7448 g$

Total density of filled ball with oxygen gas:

$\frac{0.12 g+1.7448 g}{0.560 L}=1.5442 g/L$

The ball filled with oxygen will not float in the air because total density of filled ball is greater than the density of an air.

(e) Density of the evacuated ball D = 0.214 g/L

Density of nitrogen gas = $d_4=1.165 g/L$

Mass of the nitrogen gas :

$1.165 g/L\times 0.560 L=0.6524 g$

Total density of filled ball with nitrogen gas:

$\frac{0.12 g+0.6524 g}{0.560 L}==1.3792 g/L$

The ball filled with nitrogen will not float in the air because total density of filled ball is greater than the density of an air.

f) Mass must be added to sink the ball = m

Density of ball > Density of the air ; to sink the ball.

$\frac{0.12g +m}{0.560L}>1.189 g/L$

m > 0.54584 g

For any case weight added to ball to make it sink in an air should be grater than the value of 0.54584 grams.

5 0

3 years ago

Imagine that you are outside in the cold. Your nose starts to tingle and hurt. What might you be experiencing?

KATRIN_1 [288]

D. Being cold temperatures can result in a cold nose. With prolonged exposure The body will start to lose heat faster than it can generate it, this is the result of hypothermia.

6 0

3 years ago

Read 2 more answers

Use the IUPAC nomenclature rules to give the name for this compound - Al2S3.

jonny [76]

Aluminium Sulfide
According to rules the positive specie is named first and the negative specie is named last.

6 0

3 years ago

Read 2 more answers

SHOW WORK AND INCLUDE UNITS

Ber [7]

Answer:

36365.4 Joules

Explanation:

The quantity of Heat Energy (Q) released on cooling a heated substance depends on its Mass (M), specific heat capacity (C), and change in temperature (Φ)

Thus, Q = MCΦ

Since, M = 45.4 g

C = 3.56 J/g°C,

Φ = 250°C - 25°C = 225°C

Q = 45.4g x 3.56J/g°C x 225°C

Q= 36365.4 Joules

Thus, 36365.4 Joules of heat energy is released when the lithium is cooled.

6 0

3 years ago