What is 6.3cm =____mm please help me

What neutral element has the electron configuration described by the Aufbau diagram above.

devlian [24]

Answer:

Aluminium.

Explanation:

The above electronic configuration can be written in a simplified form as shown below:

1s² 2s²2p⁶ 3s²3p¹

Next, we shall determine the number of electrons in the atom of the element as follow:

Number electron = 2 + 2 + 6 + 2 + 1

Number of electron = 13

Next, we shall determine the number of protons.

Since the element is in its neutral state,

The number of electrons and protons are equal i.e

Proton = Electron

Number of electron = 13

Proton = Electron = 13

Proton = 13

Next, we shall determine the atomic number of the element.

The atomic number of an element is simply the number of protons in the atom of the element i.e

Atomic number = proton number

Proton = 13

Atomic number = 13

Comparing the atomic number of the element with those in the periodic table, the element with the above electronic configuration is aluminium since no two elements have the same atomic number.

5 0

3 years ago

Carbon diselenide (CSe2) is a liquid at room temperature. The normal boiling point is 125°C, and the melting point is –45.5°C. C

Tema [17]

Answer:

Explanation: The strengths of the inter molecular forces varies as follows -

$CO_{2}< CS_{2} < CSe_{2}$

The normal boiling point of CSe2 is 125°C and that of CS2 is 116°C, which explains the trend that as we move down the group, the boiling point of e compound increases as the size increases.

This usually happens because larger and heavier atoms have a tendency to exhibit greater inter molecular strengths due to the increase in size . As the size increases, the valence shell electrons move far away from the nucleus, thus has a greater tendency to attract the temporary dipoles.

And larger the inter molecular forces, more tightly the electrons will be held to each other and thus more thermal energy would be required to break the bonds between them.

5 0

3 years ago

A sample of nitrogen is initially at a pressure of 1.7 kPa, a temperature of -10 C and a volume of 7.5 m3. Then the volume is de

zhannawk [14.2K]

Answer:

$\boxed{\text{2.6 kPa}}$

Explanation:

To solve this problem, we can use the Combined Gas Laws:

$\dfrac{p_{1}V_{1} }{T_{1}} = \dfrac{p_{2}V_{2} }{T_{2}}$

Data:

p₁ = 1.7 kPa; V₁ = 7.5 m³; T₁ = -10 °C

p₂ = ?; V₂ = 3.8 m³; T₂ = 200 K

Calculations:

(a) Convert temperature to kelvins

T₁ = (-10 + 273.15) K = 263.15 K

(b) Calculate the pressure

$\begin{array}{rcl}\dfrac{1.7 \times 7.5 }{263.15} & = & \dfrac{p_{2} \times 3.8}{200}\\\\0.0485 & = & 0.0190p_{2}\\p_{2} & = & \textbf{2.6 kPa}\\\end{array}\\\text{The new pressure of the gas is \boxed{\textbf{2.6 kPa}}}$