Balance the equation-<br> Al+Mn02 ——

Hi please help with this question! Need the workings.

<span>Mass of the copper penny m = 2.6 g Atomic mass of copper = 63.55, Atomic number = 29, So the number of neutrons = Atomic mass - Atomic number = 63 - 29 = 34 a. Neutron mass = 34 x (2.6 / 63.55) = 1.4 grams Copper atoms per mole = 6.040 x 10^23 atoms/mol moles of copper = 2.6 / 63.06 = 0.04123 mol Total atoms in the copper = 6.040 x 10^23 atoms/mol x 0.04123 mol = 0.25 x 10^23 atoms Number of electrons in the copper = 29 per atom Mass of the electron = 9.085 x 10^-28 g b. Electron mass = 0.25 x 10^23 x 29 x 9.085 x 10^-28 = 65.86 x 10^-5 g</span>

6 0

3 years ago

The earth's interior heat and pressure drive a process of heat transfer in the mantle called _____.

Galina-37 [17]

Convection. It is the transfer of heat by the circulation and movement of the molecules that come from liquid or gas.

5 0

3 years ago

Read 2 more answers

Find the magnitude of the resultant forces 6N and 8N inclined at an angle 240° to each<br>other.

Nana76 [90]

Answer:

F = 7.2N

Explanation:

The resultant of two forces acting at some angle is given by using the vector addition as given below

F =√F1^2+F2^2+2F1F2cosθ

Where F1 = 6N and F2 = 8N

θ = 240°

Substituting the values into the equation above

F = √ 6^2+8^2+ 2(6×8)cos240

F =√ 36+64+96cos240

F = √ 100+96 ×-0.5

F = √ 100-48

F = √ 52

F = 7.211

F = 7.2N

7 0

3 years ago

If you blow across the open end of a soda bottle and produce a tone of 250 Hz, what will be the frequency of the next harmonic h

Naddika [18.5K]

Answer:

Generally, the lowest overtone for a pipe open at one end and closed would be at y / 4 where y represents lambda, the wavelength.

Since F (frequency) = c / y Speed/wavelength

F2 / F1 = y1 / y2 because c is the same in both cases

F2 = y1/y2 * F1

F2 = 3 F1 = 750 /sec

Note that L = y1 / 4 = 3 y2 / 4 for these wavelengths to fit in the pipe

and y1 = 3 y2

8 0

3 years ago

A mass spectrometer was used in the discovery of the electron. In the velocity selector, the electric and magnetic fields are se

Mama L [17]

Answer:

Explanation:

Radius of dee, r = 8 mm = 0.008 m

Electric field, e = 400 V/m

Magnetic field, B = 4.7 x 10^-4 T

mass of electron, m = 9.1 x 10^-31 kg

charge of electron, q = 1.6 x 10^-19 C

(a) Let v is the speed of electrons.

$v = \frac{Bqr}{m}$

$v = \frac{4.7\times 10^{-4}\times 1.6\times 10^{-19}\times 0.008}{9.1 \times 10^{-31}}$

v = 661098.9 = 661099 m/s

(b)

$\frac{e}{m}=\frac{1.6 \times 10^{-19}}{9.1\times 10^{-31}}$

e / m = 1.76 x 10^14 C / kg

(c) Let K be the kinetic energy

K = 0.5 x mv²

K = 0.5 x 9.1 x 10^-31 x 661099 x 661099

K = 1.99 x 10^-19 J

K = 1.24 eV

So, the potential difference is

V = 1.24 V

(d) if the acceleration voltage is doubled

V = 2 x 1.24 = 2.48 V

So, Kinetic energy

K = 2.48 eV

K = 2.48 x 1.6 x 10^-19 = 3.968 x 10^-19 J

Let v is the speed

K = 0.5 x mv²

3.968 x 10^-19 = 0.5 x 9.1 x 10^-31 x v²

v = 933856.5 m/s

Let the new radius is r.

$r=\frac{mv}{Bq}$

$r=\frac{9.1\times 10^{-31}\times 933856.5}{4.7\times 10^{-4}\times 1.6\times 10^{-19}}$

r = 0.0113 m = 1.13 cm

7 0

3 years ago

Balance the equation- Al+Mn02 ———-> Mn + Al2O3