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3 years ago

Which of the following explain why nonmetals are typically harder and more brittle than metals?

2 answers:

6 0

Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements with high ionization energies. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite).

otez555 [7]3 years ago

3 0

directional electrons in p orbitals

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Determine the energy of 1.70 mol of photons for each of the following kinds of light. (Assume three significant figures.)PART A

BabaBlast [244]

Answer:

For A: The energy of the given amount of photons for infrared radiation is $1.271\times 10^5J$

For B: The energy of the given amount of photons for infrared radiation is $4.026\times 10^5J$

For C: The energy of the given amount of photons for infrared radiation is $1.355\times 10^6J$

Explanation:

The relationship between energy and frequency is given by Planck's equation, which is:

$E=n\rimes N_A\times \frac{hc}{\lambda}$ ......(1)

where,

h = Planck's constant = $6.62\times 10^{-34}Js$

E = energy of the light

c = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength of light

$N_A$ = Avogadro's number = $6.022\times 10^{23}$

n = number of moles of photons = 1.70 moles

Conversion factor used: $1m=10^9nm$

For A:

Wavelength of infrared radiation = $1600nm=1.6\times 10^6m$

Putting values in equation 1, we get:

$E=1.7\times 6.022\times 10^{23}\times \frac{6.62\times 10^{-34}\times 3\times 10^8}{1.6\times 10^{-6}}\\\\E=1.271\times 10^5J$

Hence, the energy of the given amount of photons for infrared radiation is $1.271\times 10^5J$

For B:

Wavelength of visible light = $505nm=5.05\times 10^7m$

Putting values in equation 1, we get:

$E=1.7\times 6.022\times 10^{23}\times \frac{6.62\times 10^{-34}\times 3\times 10^8}{5.05\times 10^{-7}}\\\\E=4.026\times 10^5J$

Hence, the energy of the given amount of photons for infrared radiation is $4.026\times 10^5J$

For C:

Wavelength of ultraviolet radiation = $150nm=1.5\times 10^7m$

Putting values in equation 1, we get:

$E=1.7\times 6.022\times 10^{23}\times \frac{6.62\times 10^{-34}\times 3\times 10^8}{1.5\times 10^{-7}}\\\\E=1.355\times 10^6J$

Hence, the energy of the given amount of photons for infrared radiation is $1.355\times 10^6J$

3 0

3 years ago

Hydrazine (N2H4), a rocket fuel , reacts with oxygen to form nitrogen gas and water vapor. The reaction is represented with the

Serggg [28]

85.33 grams of hydrazine is needed for the reaction.

Rocket fuel contains the reaction between hydrazine and oxygen to break and form nitrogen and water vapour along with steam as it is an exothermic reaction.

<h3>How to calculate the hydrazine amount?</h3>

The reaction can be shown as:

$\rm N_{2}H_{4}(l) + O_{2}(g) \rightarrow N_{2}(g) + 2H_{2}O(g)$

From the periodic chart, it can be said that:

Mass of nitrogen = 14 gm
Mass of oxygen = 16 gm
Mass of hydrogen = 1 gm

The molar mass of hydrazine will be:

$\begin{aligned} \rm Molar \;mass \;of \rm \;N_{2}H_{4}&= 2(14) + 4(1) \\\\&= 32 \;\rm grams\end{aligned}$

Mass of water:

$\begin{aligned}&= 2(1) + 16 \\\\&= 18 \;\rm grams\end{aligned}$

From the reaction, it can be said that,

1 mole of $\rm N_{2}H_{4}$ = 2 moles of $\rm H_{2}O$

32 grams of $\rm N_{2}H_{4}$ = ? grams of water

$\begin{aligned}\text{Gram of water} &= 18 \times 2\\\\&= 36 \;\rm gm\end{aligned}$

So, for 96 gm of water the hydrazine produced will be,

$\begin{aligned}\text{mass of }\rm N_{2}H_{4} &= \dfrac{96 \times 32}{36}\\\\&= 85.3334 \;\rm grams \end{aligned}$

Therefore, 85.33 grams of hydrazine is needed for the reaction.

Learn more about rocket fuel here:

brainly.com/question/10179270

7 0

2 years ago

How many grams are in 6.53 moles of Pb

dezoksy [38]

Mr: 207.2
m=n×Mr= 6.53×207.2= 1353.02g

7 0

3 years ago

When NaCl dissolves in water

slava [35]

The sodium ion becomes hydrated. when sodium chloride dissolves in water, the sodium and chloride ions and the polar water molecules are strongly attracted to one another by ion-dipole interactions

6 0

3 years ago

How are the periods, or horizontal rows, on a periodic table ordered from left to right? (2 points)

Anarel [89]

#2
They are ordered by increasing number of protons (aka atomic number)

6 0

4 years ago

Read 2 more answers