Answer:
One gram of carbon dioxide contains 13.6 x 10²¹ number of molecules.
Explanation:
Mirrors reflect light and lenses refract light.
Mirrors form images by reflecting all light that is incident on their surface, which allows us to see the reflections of objects in mirrors. Lenses, on the other hand, bend light and allow it to pass through them. The bending of light is used to form enlarged images, and for many other purposes as well.
Answer:
720 mL
Explanation:
To answer this problem we'll use the <em>definition of molarity</em>:
- Molarity = moles / liters
With that in mind we can <u>calculate the volume in liters</u>:
- 0.25 M = 0.18 moles / liters
Finally we<u> convert liters to mL</u>:
Thus 720 mL of 0.25 M NaOH would have 0.18 moles of NaOH.
Answer:
(a). 132 × 10^-9 s = 132 nanoseconds.
(b)..176.5 pico-seconds.
Explanation:
(a). At one torr, the first thing to do is to find the speed and that can be done by using the formula below;
Speed = [ (8 × R × T)/ Mm × π]^1/2.
Where Mm = molar mass, T = temperature and R = gas constant.
Speed= [ ( 8 × 8.314 × 300)/ 131.293 × π × 10^-3)^1/2. = 220m/s.
The next thing to do now is to calculate for the degree of collision which can be calculated by using the formula below;
Degree of collision = √2 × π × speed × d^2 × pressure/ K × T.
Note that pressure = 1 torr = 133.32 N/m^2 and d = collision diameter.
Degree of collision = √2 × π × 220 × (4.9 × 10^-10)^2 × 133.32/ 1.38 × 10^-23 × 300.
Degree of collision = 7.55 × 10^6 s^-1.
Thus, 1/ 7.55 × 10^6. = 132 × 10^-9 s = 132 nanoseconds.
(b). At one bar;
1/10^5 × 10^3 × 56.65 = 1.765 × 10^-10 = 176.5 pico-seconds.
Answer:
The naswer to your question is Scandium
Explanation:
43 means the atomic mass is normally presented as a power
21 means atomic number is always a subscript
₂₁ ? ⁴³
Technetium ₄₃Tc⁹⁸
Scandium ₂₁Sc⁴⁴
Titanium ₂₁Ti⁴⁷
Cobalt ₂₇Co⁵⁹
