If we guide ourselves with the Moh´s scale:
Material scratches apatite → material is harder than 5.
Material is scratched by corundum → material is softer than 9.
Conclusion:
The hardness of the unknown material stands between 5 and 9.
Note:
Both apatite and corundum are defining materials (reference materials in the Moh´s scale). So, you can also give an answer using defining materials:
"It can either be an orthoclase feldspar, a quartz or a topaz".
Hope it helped,
BiologiaMagister
<u><em>This answer is dedicated to JaySL</em></u>
Answer:
Compressions and Rarefactions
<em>A vibrating tuning fork is capable of creating such a longitudinal wave. As the tines of the fork vibrate back and forth, they push on neighboring air particles. The forward motion of a tine pushes air molecules horizontally to the right and the backward retraction of the tine creates a low-pressure area allowing the air particles to move back to the left.</em>
Explanation:
These regions are known as compressions and rarefactions respectively. The compressions are regions of high air presure while the rarefactions are regions of low air pressure.
<em>Sound waves can also be shown in a standard x vs y graph, as shown here. This allows us to visualise and work with waves from a mathematical point of view. The resulting curves are known as the "waveform" (i.e. the form of the wave.) The wave shown here represents a constant tone at a set frequency.</em>
Answer:
C. Makes energy in cells
Explanation:
Nitrogen has the role of making energy in cells of the human body.
Answer:
The correct answer is - 38.15 gm of NaCl.
Explanation:
Write the balanced equation for this reaction of sodium (Na) and chlorine (Cl₂) to produce sodium chloride (NaCl):
2Na + Cl₂ —> 2NaCl
the mass of Na and the mass of NaCl :
Molar mass of Na = 23 g/mol
In the balanced equation = 2 × 23 = 46 g
Molar mass of NaCl = 23 + 35.5
= 58.5 g/mol
similarly in balanced equation = 2 × 58.5 = 117 g
From the balanced equation above,
46 g of Na reacted to produce 117 g of NaCl.
By converting it to 15 grams of Na.
Therefore,15 g of Na will react to produce = (15 × 117)/46 = 38.15 g of NaCl.
Thus, 38.15 g of Na
Answer:
The binomial name consists of a genus name and specific epithet. The scientific names of species are italicized. The genus name is always capitalized and is written first; the specific epithet follows the genus name and is not capitalized. There is no exception to this.
