Explanation:
An observation that can be counted is known as quantitative observation. On the other hand, an observation that does not contain any numerical data is known as non-quantitative observation.
Therefore, given observations are classified as follows.
(a) The Sun rises in the east - It is a non-quantitative observation as it cannot be measured.
(b) A person weighs one-sixth as much on the Moon as on Earth - It is a quantitative observation as it can be measured because we know the mass of moon. Hence, we can find out the weight of person.
(c) Ice floats on water - It is a non-quantitative observation as it cannot be measured.
(d) A hand pump cannot draw water from a well more than 34 ft deep _ It is a quantitative observation because it is measure that more than 34 ft deep water cannot be drawn by the pump.
The answer that h are looking for is c
Answer:
The mixture of cryolite and aluminum oxide has a lower melting point than pure aluminum oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.
Explanation:
Answer:
a) f = 3.02x10¹⁵ s⁻¹, and λ = 99.4 nm.
b) 99.4 nm
Explanation:
a) The energy of radiation is given by:
E = h*f
Where h is the Planck constant (6.626x10⁻³⁴ J.s), and f is the frequency. To have the highest frequency, the energy must be the highest too, because they're directly proportional. So we must use E = -E1 = 20x10⁻¹⁹ J
20x10⁻¹⁹ = 6.626x10⁻³⁴xf
f = 3.02x10¹⁵ s⁻¹
The wavelenght is the velocity of light (3.00x10⁸ m/s) divided by the frequency:
λ = 3.00x10⁸/3.02x10¹⁵
λ = 9.94x10⁻⁸ m = 99.4 nm
b) To have the shortest wavelength, it must be the highest energy and frequency, so it would be the same as the letter a) 99.4 nm.
False
explanation
All of the elements with atomic numbers 1 to 92 can be found in nature, have stable or very long half-life isotopes, and are created as common products of the decay of uranium and thorium.
