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Mrac [35]
3 years ago
11

What would you expect to have the highest melting point?

Chemistry
1 answer:
Georgia [21]3 years ago
6 0

Answer:

it is expected that highest melting points correspond to compound with high molecular weight with more force of attractions within the moleules

Explanation:

You might be interested in
The radioactive isotope of lead, Pb-209, decays at a rate proportional to the amount present at time t and has a half-life of 3.
Marina86 [1]

Answer:

Therefore it will take 7.66 hours for 80% of the lead decay.

Explanation:

The differential equation for decay is

\frac{dA}{dt}= kA

\Rightarrow \frac{dA}{A}=kdt

Integrating both sides

ln A= kt+c₁

\Rightarrow A= e^{kt+c_1}

\Rightarrow A=Ce^{kt}         [e^{c_1}=C]

The initial condition is A(0)= A₀,

\therefore A_0=Ce^{0.k}

\Rightarrow C=A_0

\therefore A=A_0e^{kt}.........(1)

Given that the Pb_{209}  has half life of 3.3 hours.

For half life A=\frac12 A_0 putting this in equation (1)

\frac12A_0=A_0e^{k\times3.3}

\Rightarrow ln(\frac12)= 3.3k     [taking ln both sides, ln \ e^a=a]

\Rightarrow k=\frac{ln \frac12}{3.3}

⇒k= - 0.21

Now A₀= 1 gram, 80%=0.8

and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram

Now putting the value of k,A and A₀in the equation (1)

\therefore 0.2=1e^{(-0.21)\times t}

\Rightarrow e^{-0.21t}=0.2

\Rightarrow -0.21t= ln(0. 2)

\Rightarrow t= \frac{ln (0.2)}{-0.21}

⇒ t≈7.66

Therefore it will take 7.66 hours for 80% of the lead decay.

3 0
3 years ago
The mass of an electron is 9.11× 10–31 kg. What is the uncertainty in the position of an electron moving at 2.00 × 106 m/s with
Kruka [31]
Just use the Heisenberg Uncertainty principle: 

<span>ΔpΔx = h/2*pi </span>

<span>Δp = the uncertainty in momentum </span>
<span>Δx = the uncertainty in position </span>
<span>h = 6.626e-34 J s (plank's constant) </span>

<span>Hint: </span>

<span>to calculate Δp use the fact that the uncertainty in the momentum is 1% (0.01) so that </span>

<span>Δp = mv*(0.01) </span>

<span>m = mass of electron </span>
<span>v = velocity of electron </span>

<span>Solve for Δx </span>

<span>Δx = h/(2*pi*Δp) </span>

<span>And that is the uncertainty in position. </span>
6 0
4 years ago
What is the speed of light?can a object move in speed of light?​
timurjin [86]

Answer:

The speed of light is the speed at which light travels. No, an object cannot move at the speed of light.  

Explanation:

The speed of light is 186,000 miles per second. An object with mass cannot move at the speed of light since it would take an infinite amount of energy to achieve that velocity, since only massless particles can travel at the speed of light. Also, you would have to factor in air friction, meaning even if an object were to reach such high speeds, it would instantly disintegrate.

4 0
2 years ago
What is the ph of a peach with a [ –oh] = 3.2 × 10 –11 m?
iogann1982 [59]
H+= 10^-14 / [OH-1 = 3.125 * 10^-4 M
pH=-log(H+) = 3.505

Just round it down and your answer = 3.5
3 0
2 years ago
Fats help your brain and nervous system develop correctly.<br> True<br> False
Fantom [35]

Answer:

Yes

Explanation:

the amino acids in proteins and the fatty acids in fat replace the amino and fatty acids in your brain to help you function and develop correctly.

6 0
3 years ago
Read 2 more answers
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