An element, X, has 2 electron shells and 5 of the electrons are valence electrons. The atomic number of element X would be:

Give an example of how each compound is used or found in nature. Be sure to use complete sentences.

puteri [66]

Water is found in lakes and rivers. Its purpose in nature is to hydrate animals

Hydrogen gas is not abundant in nature, but hydrogen is abundant in water. Hydrogen (bonds) help ice float. Otherwise, freezing lakes would kill animals (it actually doesn't since the ice creates a "coat" above the water").

Ammonia is nitrogen-rich molecules that plant uses to get their nitrogen. It comes from the part of the nitrogen cycle where dead plants and animals are decayed.

Carbon dioxide is what we exhale. Plants "inhale" carbon dioxide and use that for photosynthesis.

Hydrogen sulfide is emitted by volcanoes and by anaerobic (oxygen-less) decay from bacteria.

Have an awesome day! I hope this helps.

8 0

3 years ago

An aqueous solution contains 0.100 m naoh at 25.0 °c. the ph of the solution is ________.

ikadub [295]

Recall; pH + pOH = 14
In this case [OH-] =0.100 m
therefore;
pOH = -LOG[OH-]
= - Log (0.100)
= 1.00
Therefore; the pOH is 1.00
And since, pH +pOH = 14
Then pH = 14-pOH
= 14 -1
= 13
Thus the pH is 13.00

7 0

3 years ago

A certain hydrocarbon has a molecular formula of C9H16. Which of the following is not a structural possibility for this hydrocar

snow_tiger [21]

Answer: Option (d) is the correct answer.

Explanation:

It is given that molecular formula is $C_{9}H_{16}$ . Now, we will calculate the degree of unsaturation as follows.

Degree of unsaturation = $C_{n} - \frac{\text{monovalent}}{2} + \frac{\text{trivalent}}{2} + 1$

= $9 - \frac{16}{2} + 1$

= 9 - 8 + 1

= 2

As the degree of unsaturation comes out to be 2. It means that this compound will contain one ring and one double bond.

Yes, this compound could be an alkyne as for alkyne D.B.E = 2.

But this compound cannot be a cycloalkane because for a cycloalkane D.B.E = 1 which is due to the ring only.

Thus, we can conclude that it is a cycloalkane is not a structural possibility for this hydrocarbon.

6 0

3 years ago

1. What pressure would be exerted by 46.0grams of hydrogen gas placed into a 3.00 L container at

dlinn [17]

Answer:

187.34 atm

Explanation:

From the question,

PV = nRT.................. Equation 1

Where P = Pressure, V = Volume, n = number of mole, R = molar gas constant, T = Temperature.

make P the subject of the equation

P = nRT/V.............. Equation 2

n = mass(m)/molar mass(m')

n = m/m'............... Equation 3

Substitute equation 3 into equation 2

P = (m/m')RT/V............ Equation 4

Given: m = 46 g, T = 25°C = (25+273) = 298 K, V = 3.00 L

Constant: m' = 2 g/mol, R = 0.082 atmL/K.mol

Substitute these values into equation 4

P = (46/2)(0.082×298)/3

P = (23×0.082×298)/3

P = 187.34 atm

3 0

3 years ago

The equilibrium constant for the reaction

Hitman42 [59]

The question is incomplete, here is the complete question:

The equilibrium constant for the reaction

N₂O₄(g)⇌2NO₂ at 2°C is Kc = 2.0

If each yellow sphere represents 1 mol of N₂O₄(g) and each gray sphere 1 mol of NO₂ which of the following 1.0 L containers represents the equilibrium mixture at 2°C?

The image is attached below.

Answer: The system which represents the equilibrium having value of $K_c=2.0$ is system (b)

Explanation:

Equilibrium constant in terms of concentration is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_c$