Answer:
17.3 g
Explanation:
<u>Given the following data;</u>
- Quantity of heat, Q = 0.507 J
- Temperature = 0.007°C
- Specific heat capacity of water = 4.2 J/g°C
Mathematically, Heat capacity is given by the formula;

Where;
- Q represents the heat capacity or quantity of heat.
- M represents the mass of an object.
- C represents the specific heat capacity of water.
- T represents the temperature.
Making "M" the subject of formula, we have;

Substituting the values into the formula, we have;


<em>Mass, m = 17.3 grams</em>
The atmosphere is a mixture of gasses.
ANSWER
2 valence electrons
STEP-BY-STEP EXPLANATION:
The electronic configuration is given below as

Looking at the configuration, you will see that the last energy carries 2 electrons
Hence, the valence electrons are 2
<u>Answer:</u> The spacing between the crystal planes is 
<u>Explanation:</u>
To calculate the spacing between the crystal planes, we use the equation given by Bragg, which is:

where,
n = order of diffraction = 2
= wavelength of the light =
(Conversion factor:
)
d = spacing between the crystal planes = ?
= angle of diffraction = 22.20°
Putting values in above equation, we get:

Hence, the spacing between the crystal planes is 