Models need to be changed when ______

Which of the following is a polar molecule?

mixer [17]

the answer is option b

7 0

3 years ago

Electrons are found in energy levels around the nucleus of an atom. Energy levels can also be called ""shells."" The energy leve

melamori03 [73]

Answer:

The first electronic shell or energy level, having n= 1, called the K shell, is the closest to the nucleus.

Explanation:

In an atom, the sub atomic particles called electrons, revolve around the nucleus of the given atom at different energy levels, called shells.

The energy levels or the electronic shells are denoted by the principal quantum number (n) and has the following values n = 1, 2, 3, 4, 5, 6, 7; from the innermost shell to the outermost.

The electron shells are also labelled by the alphabets, K, L, M, N, O, P, and Q, from the innermost shell to the outermost.

Thus the first electronic shell having n= 1, called K shell, is the lowest energy level and is present closest to the nucleus.

Whereas, the last electronic shell having n =7, called Q shell, is the highest energy level and is farthest from the nucleus.

5 0

3 years ago

Strigol is an important plant hormone that is released by crops such as rice and sugarcane. Unfortunately for these plants, stri

Len [333]

The hydrogen deficiency index( HDI) of strigol is = 10

<h3>How to calculate HDI:</h3>

The hydrogen deficiency index is used to measure the number of degree of unsaturation of an organic compound.

Strigol is an example of an organic compound because it contains carbons and hydrogen.

To calculate the HDI using the molecular formula given (C19H20O6) the formula for HDI is used which is:

$hdi = \frac{1}{2} (2c + 2 + n - h - x)$

where C = number of carbon atoms = 19

n= number of nitrogen atoms = 0

h= number of hydrogen atoms = 20

X = number of halogen atoms = 0

Note that oxygen was not considered because it forms two bonds and has no impact.

There for HDI =

$\frac{1}{2} (2 \times 19 + 2 + 0 - 20 - 0)$

HDI=

$\frac{1}{2} (40 - 20)$

HDI =

$\frac{1}{2} \times 20$

HDI = 10

Therefore, the hydrogen deficiency index of strigol is = 10

Learn more about unsaturated compounds here:

brainly.com/question/490531

7 0

3 years ago

How is steam different from water vapour

trapecia [35]

Steam is made from boiling things and water vapor is from boiling water.

7 0

3 years ago

Read 2 more answers

The reaction is proceeding at a rate of 0.0080 Ms-1 in 50.0 mL of solution in a system with unknown concentrations of A and B. W

Leokris [45]

Answer:

0.0010 mol·L⁻¹s⁻¹

Explanation:

Assume the rate law is

rate = k[A][B]²

If you are comparing two rates,

$\dfrac{\text{rate}_{2}}{\text{rate}_{1}} = \dfrac{k_{2}\text{[A]}_2[\text{B]}_{2}^{2}}{k_{1}\text{[A]}_1[\text{B]}_{1}^{2}}= \left (\dfrac{\text{[A]}_{2}}{\text{[A]}_{1}}\right ) \left (\dfrac{\text{[B]}_{2}}{\text{[B]}_{1}}\right )^{2}$

You are cutting each concentration in half, so

$\dfrac{\text{[A]}_{2}}{\text{[A]}_{1}} = \dfrac{1}{2}\text{ and }\dfrac{\text{[B]}_{2}}{\text{[B]}_{1}}= \dfrac{1}{2}$

Then,

$\dfrac{\text{rate}_{2}}{\text{rate}_{1}} = \left (\dfrac{1}{2}\right ) \left (\dfrac{1}{2}\right )^{2} = \dfrac{1}{2}\times\dfrac{1}{4} = \dfrac{1}{8}\\\\\text{rate}_{2} = \dfrac{1}{8}\times \text{rate}_{1}= \dfrac{1}{8}\times \text{0.0080 mol$\cdot$L$^{-1}$s$^{-1}$} = \textbf{0.0010 mol$\cdot$L$^{-1}$s$^{-1}$}\\\\\text{The new rate is $\large \boxed{\textbf{0.0010 mol$\cdot$L$^\mathbf{{-1}}$s$^{\mathbf{-1}}$}}$}$

8 0

3 years ago

Models need to be changed when _______.