Zn(s)+Cu^2+(aq)—->Zn^2+(aq)

Express the frequency in inverse seconds of n=4 to n=3

HACTEHA [7]

Answer:

1.60×10¹⁴ s⁻¹

Explanation:

When an electron jumps from one energy level to a lower energy level some energy is released in the form of a photon.

4 0

3 years ago

If a bullet travels at 407.0 m/s, what is its speed in miles per hour? Number click to edit mi/h For the same bullet travelling

kaheart [24]

Answer : The speed in miles per hour is 22 mile/hr.

The speed in yard per min is 26617.8 yard/min

Explanation :

The conversion used for meters to miles is:

$1m=100cm\times \frac{1in}{2.54cm}\times \frac{1ft}{12in}\times \frac{1mile}{5280ft}$

The conversion used for second to hour is:

$1s=\frac{1}{60}min\times \frac{1hr}{60min}$

The conversion used for meter per second to mile per hour is:

$1\frac{m}{s}=\frac{100cm\times \frac{1in}{2.54cm}\times \frac{1ft}{12in}\times \frac{1mile}{5280ft}}{\frac{1}{60}min\times \frac{1hr}{60min}}$

As we are given the speed of 407.0 meter per second. Now we have to determine the speed in miles per hour.

$1m/s=2.2mile/hr$

So, $407.0m/s=\frac{2.2mile/hr}{1m/s}\times 407.0m/s=895.4mile/hr$

Therefore, the speed in miles per hour is 22 mile/hr.

The conversion used for meter to yard

1m = 1.09 yard

The conversion used for second to hour is:

$1s=\frac{1}{60}min$

The conversion used for meter per second to mile per hour is:

$1m/s=\frac{1.09yard}{frac{1}{60min}}$

$1m/s=65.4yard/min$

As we are given the speed of 407.0 meter per second. Now we have to determine the speed in yards per min

$1m/s=65.4yard/min$

So, $407.0m/s=\frac{65.4yard/min}{1m/s}\times 407.0m/s=26617.8yard/min$

Therefore, the speed in yard per min is 26617.8 yard/min

7 0

3 years ago

2. As NH4OH is added to an HCl solution, the pH of the solution

chubhunter [2.5K]

Answer:

c

Explanation:

Nh4OH + HCL ---> NH4Cl + H3O

so ph decreases as H3O increases

and OH also decreases

5 0

3 years ago

Read 2 more answers

It took 55 days for a radioactivity of 1.75 x 1012 Bq to remain 0.135 Ci. What is the half-life of this radioactivity?

Mnenie [13.5K]

From the calculations, the half life of the material is 6.5 days.

<h3>What is radioactivity?</h3>

The term radioactivity has to do with the spontaneous disintegration of a specie.

Uisng the formula;

N=Noe^-kt

N= amount at time t = 0.135 Ci or 4.995 ×10^9 Bq

No = amount initially present = 1.75 x 10^12 Bq

k = rate constant = ?

t = time taken = 55 days

Hence;

4.995 ×10^9 = 1.75 x 10^12e^-55k

4.995 ×10^9/1.75 x 10^12 = e^-55k

2.85 * 10^-3 = e^-55k

ln2.85 * 10^-3 = -55k

k = ln2.85 * 10^-3/-55

k = 0.1066 day-1

Half life = 0.693/ 0.1066 day-1

= 6.5 days

Learn more about radioactivity:brainly.com/question/1770619

#SPJ1

4 0

1 year ago

1. 2.0 mL/s x 4.0 hrs = ? L<br><br> How do you do this conversion problem

Phantasy [73]

Answer:

29 L.

Explanation:

Hello!

In this case, considering that we are performing a conversion by which the time should be cancelled out to obtain liters, we first need to convert the seconds on bottom to hours and then the volume on top to liters, just a shown down below:

$2.0\frac{mL}{s} *\frac{1L}{1000mL} *\frac{3600s}{1hr}*4.0hr\\\\=28.8L$

Which turns out 29 L with 2 significant figures.

Best regards!

6 0

3 years ago