All categories

2 years ago

Please help! Will mark Brainliest!

Chemistry

2 answers:

Cerrena [4.2K]2 years ago

8 0

Answer:

B. and D.

Explanation:

Elina [12.6K]2 years ago

6 0

The answer is D ya know

You might be interested in

How to Balance __MgF2 + __Li2CO3 + __ LiF

Andru [333]

__MgF2 + __Li2CO3 + __ 2LiF

7 0

2 years ago

First person with the right answer gets brainliest thanks (btw the numbers on the right are the answers choose the right one)

kap26 [50]

Molar mass of FE2O3=2(55.85)+3(16)=159.7

2.56g*1mol/159.7*2mol/1mol*55.85g/1mol=1.79g

6 0

2 years ago

What happens when an electron moves from n=2 to n=5?

Aleksandr-060686 [28]

Answer:

Explanation:

10?

4 0

2 years ago

The energy E of the electron in a hydrogen atom can be calculated from the Bohr formula: E = R_y/n^2 In this equation R_y stands

Katarina [22]

Answer:

The wavelength of the line in the emission line spectrum of hydrogen caused by the transition of the electron for the given energy levels is $5.23\times 10^{-5} m$

Explanation:

Given :

The energy E of the electron in a hydrogen atom can be calculated from the Bohr formula:

$E=\frac{R_y}{n^2}$

$R_y=2.18\times 10^{-18} J$ = Rydberg energy

n = principal quantum number of the orbital

Energy of 11th orbit = $E_{11}$

$E_{11}=\frac{2.18\times 10^{-18} J}{11^2}=1.80\times 10^{-20} J$

Energy of 10th orbit = $E_{10}$

$E_{10}=\frac{2.18\times 10^{-18} J}{10^2}=2.18\times 10^{-20} J$

Energy difference between both the levels will corresponds to the energy of the wavelength of the line which can be calculated by using Planck's equation.

$E'=E_{10}-E_{11}=2.18\times 10^{-20} J-1.80\times 10^{-20} J$

$=E'=0.38\times 10^{-20} J$

$\lambda =\frac{hc}{E'}$ (Planck's' equation)

$\lambda = \frac{6.626\times 10^{-34} Js\times 3\times 10^8 m/s}{0.38\times 10^{-20} J}$

$\lambda = 5.2310\times 10^{-5} m\approx 5.23\times 10^{-5} m$

The wavelength of the line in the emission line spectrum of hydrogen caused by the transition of the electron for the given energy levels is $5.23\times 10^{-5} m$

3 0

2 years ago

How much heat do you need to raise the temperature of 150 g of ice from -30°C to -15°c?

OLga [1]

To solve this question, you must use the formula: q=mc(change in temperature), where q is heat, m is mass, C is specific heat and temperature change is temperature change. The specific heat for ice is 2.1kJ/Kg x K (given). The change in temperature is 15 degrees Celsius (which you should change to kelvins so you can cancel out units), or 273 + 15 = 288K. The mass is 150 grams, which is 0.15 kg. Now, we can solve for q, heat. We will do this by substituting variables into the formula. After simplifying and cancelling out units, the answer we get is: 90.72kJ.

4 0

2 years ago