I think is near the ozone layer, i am not sure
Answer:
1. The precession of the equinoxes.
2. Changes in the tilt angle of Earth’s rotational axis relative to the plane of Earth’s orbit around the Sun.
3. Variations in the eccentricity
Explanation:
These variations listed above; the precession of the equinoxes (refers, changes in the timing of the seasons of summer and winter), this occurs on a roughly about 26,000-year interval; changes in the tilt angle of Earth’s rotational axis relative to the plane of Earth’s orbit around the Sun, this occurs roughly in a 41,000-year interval; and changes in the eccentricity (that is a departure from a perfect circle) of Earth’s orbit around the Sun, occurring on a roughly 100,000-year timescale. which influences the mean annual solar radiation at the top of Earth’s atmosphere.
This statement is True, Because the phenomenon is called a Mirage!
Answer:
Explanation:
a) Hardness is a measure of the resistance of a material to permanent deformation (plastic) on its surface,
Hardness tests play an important role in material testing, quality control and component acceptance.
Hardness test are needed to be perform as a <em>quality assurance procedure</em>, to validate materials are according to the specific hardness required,
We depend on the data to verify the quality of the components to determine if a material has the necessary properties for its intended use.
Through the years, the establishment of increasingly productive and effective means of testing, has given way to new cutting-edge methods that perform and interpret hardness tests more effectively than ever. The result is a greater capacity and dependence on "letting the instrument do the work", contributing to substantial increases in performance and consistency and continuing to make hardness tests very useful in industrial and R&D applications.
b)
- <u>Instrumental errors</u>: Instrument calibration is extremely important. An instrument with expired calibration may be generating erroneous data systematically.
- <u>Enviromental error: </u>An example is when surface preparation of the sample to be tested is poor, then the error can be presented when measuring the indentation on the sample to determine the hardness value.
This problem can be solved by using oxidation states. The oxidation state is based on the electrons an atom loses or gain, or appears to use when forming compounds.To find the formula for Copper (I) Sulfide, we have to first consider the individual ions that come together to form it. Copper (I) is an ion of copper that has a charge of +1, i.e 
. Sulfur is an element in group 6 of the periodic table. The sulfur ion has a charge of -2, i.e 
. To form Copper (I) Sulfide, which is electrically neutral, we need 2 Copper (I) ions and 1 sulfur ion.
.
The reaction is represented by the equation below
.
The correct answer is (C)
