Answer:
The adjustable legs and the table of sand.
<em>Note:The question is incomplete. The complete question is given below.</em>
Using Models to Answer Questions About Systems
Armando’s class was looking at images of rivers formed by flowing water. Most of the rivers were wide and shallow, but one river was narrow and deep. Armando’s class thinks that this river is narrow and deep because:
- the hill that the water flowed down was very steep, or
- the sand grains that the water flowed through were very small.
Armando designed the model below to try to answer the question: Why is this river so narrow and deep?
Explanation:
The model designed by Armando will be helpful to answer the question because of the following features it possesses:
1. An adjustable leg- since one of the hypotheses put forward by the class to explain why the river was narrow and deep was that the hill that the water flowed down was very steep, the adjustable legs can be lowered or raised in order to make the slope shallower or steeper so that their hypothesis can be tested.
2. A table of sand- the table of sand serves as the streambed. By adjusting the size of the sand grains to be larger or smaller, the students will be able to to test their second hypothesis that the small size sand grains that the water flowed through was the reason for the river to be narrow and deep.
The results of their experiments will enable them to come to a conclusion.
Answer:
Explanation:
A <em>combustion reaction</em> is the reaction with oxygen along with the release of energy in form of heat or light.
Organic compounds (like CH₄) undergo combustion forming water and CO₂.
The combustion reaction of CH₄ is:
Hence, the first equation from the choices is not showing the combustion reaction of CH₄.
Not only organic compounds can undergo combustion. Metals and no metals can undergo combustion, i.e. metals and no metals can react with oxygen releasing light or heat.
The reaction of copper and oxygen (second choice) is a combustion reaction:
The formation of water (2H₂ + O₂ → 2H₂O) is other example of a combustion reaction where no organic compounds are involved.
On the other hand, the other two equations from the choice list are not reactions with oxygen, so they do not show combustion reactions.
Answer:uclear Force that holds together the nucleus of an atom. electromagnetic force. ... They are unstable because the Strong Force that would hold them together if the protons and neutrons were closer is weakened because the protons and neutrons get too far apart.
Explanation:
Explanation:
Copper (II) sulfate is usually present as a hydrous state, which is of the form CuSO4 * nH2O, where n is a whole number.
Mass of sample (CuSO4 * nH2O)
= 152.00g - 128.10g = 23.90g.
Mass of water loss during heating
= 152.00g - 147.60g = 4.40g.
Molar mass of H2O = 18g/mol
Moles of H2O in sample
= 4.40g / (18g/mol) = 0.244mol.
Mass of anhydrous sample (CuSO4)
= 23.90g - 4.40g = 19.50g
Molar mass of CuSO4 = 159.61g/mol
Moles of CuSO4 in sample
= 19.50g / (159.61g/mol) = 0.122mol.
Since mole ratio of CuSO4 to H2O
= 0.122mol : 0.244mol = 1:2, n = 2.
Hence we have CuSO4 * 2H2O.
Answer: 8.12 g NaCl
Explanation: Use Avogadro's number to find the number of m
moles of NaCl:
8.24x10²² molecules NaCl / 1 mole NaCl/ 6.022x10²³ molecules NaCl
= 0.14 mole NaCl
Next convert moles to grams NaCl using its molar mass;
0.14 mole NaCl x 58g NaCl / 1 mole NaCl
= 8.12 g NaCl
