The proceeds of respiration, where living matter, produces the product of CO2 upon exhalation would be contributing to the Carbon cycle.
Answer:
- <em>The substance that cannot be broken down by a chemical change is </em><u>tungsten (option C)</u>
Explanation:
Chemical compounds are pure <em>substances</em> constituted by two or more different elements. They have fixed composition and have their unique chemical properties, different from their individual components (elements) and from other compounds.
Thus chemical compounds can<em> be broken down by a chemical change</em> into their individual atoms or other simpler compounds.
The substances indicated by the choices <em>A) methane, B) propanal, and D) water</em>, are chemical compounds with chemical formulae CH₄, C₃H₆O, and H₂O, respectively, so they<em> can be broken down into their consitutents by a chemical change</em>.
On the other hand, <em>tungsten</em> is one of the 118 known elements. Its atomic number is 74, and its chemical symbol is W.
Then, being tungsten an element, which means that all the atoms present in a pure sample have the same number of protons and electrons, it <em>cannot be broken down by a chemical change</em>. The only way to split an atom of tungsten is by a nuclear reaction.
Answer:
20 g of CO₂ have 5.47x10²³ oxygen atoms
Explanation:
1 mol of CO₂ has 1 mol of C and 2 moles of O.
Mass / Molar mass = Moles
20 g / 44 g/m = 0.454 moles
In 1 mol we find 2 moles of O
In 0.454 moles of CO₂, we will find ( 0.454 .2) = 0.909 moles
1 mol has _____ 6.02x10²³ atoms
0.909 moles have (0.909 . 6.02x10²³) = 5.47x10²³ atoms
Answer:
D. Individual N would have done less work because the object was moved a shorter distance
Explanation:
When a body is moved a given distance (x) by a specific force (F), the work done on the body is equivalent to F*x. This shows that work is proportional to the applied force and the distance traveled by the body. Therefore, the higher the distance the higher the work done and the lower the distance the lower the work done. The work done by Individual N is lower due to the shorter limbs that correspond to shorter distance.