_______ are events that disrupt the stability of a whole ecosystem.
A.Resources
B.Disturbances
C.Species
Which kind of energy is stored in the chemical bonds of molecules found in
wood?
A. Mechanical energy
B. Potential energy
C. Gravitational energy
D. Kinetic energy
Answer:
B. Potential energy
Explanation:
It's not mechanical energy, because it is not doing work
It's not kinetic energy because it;s not moving
It's not gravitational energy because it is not above the ground
It is potential energy because it is stored energy
What is the simplest whole number ratio of atoms in a molecule or formula unit called?
the molecular formula
the molar mano
the percent composition
the empirical formula
PLEASE HELPP
what are the characteristics or properties that you can use to classify elements
Answer:
The number of outermost energy level electrons ( valency electrons )
The atomic number
What do you notice about the distance between the terrestrial planets compared with the spacing between the gas giants
Answer:
The spacing between the terrestrial planets is less than that between the gas planets.
Explanation:
Since the terrestrial planets which are Mercury, Venus, Earth and Mars have a distance of 0.4 AU, 0.7 A.U, 1.0 AU and 1.5 A.U respectively from while the gas planets which are Jupiter, Saturn, Uranus and Neptune have a distance of 5.2 AU, 9.6 AU, 19.6 AU and 30 AU respectively from the sun, we can see that the spacing between the terrestrial planets is much smaller than the spacing between the gas planets.
For example, the spacing between Mercury and Venus is 0.7 AU - 0.4 AU = 0.3 AU while that between Earth and Venus is 1.0 AU - 0.7 AU = 0.3 AU.
Also, the spacing between Earth and Mars is 1.5 AU - 1.0 AU = 0.5 AU.
Also too, the spacing between the gas planets is shown below the spacing between Jupiter and Saturn is 9.6 AU - 5.2 AU = 4.4 AU while that between Uranus and Saturn is 19.6 AU - 9.6 AU = 10.0 AU.
Also, the spacing between Neptune and Uranus is 30 AU - 19.6 AU = 10.4 AU.
Thus, we can see that the spacing between the terrestrial planets is less than that between the gas planets.
Note that AU means astronomical unit and 1 AU is the distance between the Earth and the Sun. 1 AU = 1.50 × 10⁸ km
how many moles are in 20 grams of argon
Answer:
There are 0.5 mole in 20g of argon.
Explanation:
40 g of argon = 1mole
Then 20g of argon is,
→ 1/40 × 20
→ 0.5 mole
Answer:
[tex]n = \frac{mass}{molar \: mass} \\ n = \frac{20g}{39.948 \frac{g}{mol} } \\ n = 0.5 \: mol \: of \: argon[/tex]
Explanation:
hope this makes sense
:)
A water pipe bursting in the winter is a result of which type of weathering?
A. Biological
B. Freeze-thaw
C. Exfoliation
D. Chemical
Answer:
Freeze-thaw
Explanation:
Water expands slightly when it freezes to form ice. This is why water pipes sometimes burst in the winter. You might have seen a demonstration of this sort of thing - a jar filled to the brim with water eventually shatters after it is put into a freezer. The formation of ice can also break rocks.
Which of the following pairs of elements is most likely to form an ionic compound?
• magnesium and sodium
• nitrogen and sulfur
• oxygen and chlorine
• magnesium and chlorine
• carbon and fluorine
Explanation:
magnesium and sodium because they are minerals and part of iron
Explain why a mixture of copper (Il) Oxide and Magnesium reacts while there is no reaction when a mixture of Copper and Magnesium Oxide is heated.
Answer:
Copper oxide + magnesium = copper + magnesium oxide
Explanation:
When copper oxide is heated with magnesium powder, then magnesium oxide and copper are formed.. For example, magnesium is more reactive than copper. ... brown copper coats the surface of the magnesium.
20 POINTS!!
What is the enthalpy of combustion when 1 mol C6H6(g) completely reacts with oxygen?
2C6H6(g) + 15O2(g) ? 12CO2(g) + 6H2O(g)
Options:
A. - 6339 kJ/mol
B. - 3169 kJ/mol
C. 1268 kJ/mol
D. 6339 KJ/mol
Answer:
-3169
Explanation:
trust the process
-3169 kJ/mol is the enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.
Explanation:
Given:
The reaction of combustion of [tex]C_6H_6(g)[/tex] along with enthalpies of formation of the compounds.
To find:
The enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.
Solution:
[tex]2C_6H_6(g) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(g)[/tex]
Enthalpy of the reaction:
[tex]\Delta H^o_{rxn}=\sum [\Delta H^o_{f,products}]-\sum [\Delta H^o_{f,reactants}]\\=[12mol\times \Delta H^o_{f.CO_2(g)}+6mol\times \Delta H^o_{f,H_2O(g)}]-[2 mol\times \Delta H^o_{f.C_6H_6(g)}+15\times \Delta H^o_{f,O_2(g)}]\\=[12mol\times (-393.50 kJ/mol)+6mol\times (-241.82 kJ/mol)]-[2mol\times 82.90kJ/mol+15mol\times 0 kJ/mol]\\=-6338.72 kJ[/tex]
[tex]2C_6H_6(g) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(g).\Delta H^o_{rxn}=-6338.72 kJ[/tex]
When 1 mole of [tex]C_6H_6(g)[/tex] reacts with oxygen gas:
[tex]=\frac{\Delta H^o_{rxn}}{\text{2 mol of } C_6H_6}\\=\frac{-6338.72 kJ}{2 mol}\\=-3169.36 kJ/mol\approx -3169 kJ/mol[/tex]
-3169 kJ/mol is the enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.
Learn more about enthalpy of combustion here:
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How much water can be produced when 18 grams of pentane is burned in air? C5H12 + 8 02 --> 5 CO2 + 6 H2O. 9.0 g 18 g 27 g 36 g 729
Answer: The mass of water produced is 27 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of pentane = 18 g
Molar mass of pentane = 72.15 g/mol
Plugging values in equation 1:
[tex]\text{Moles of pentane}=\frac{18g}{72.15g/mol}=0.250 mol[/tex]
The given chemical equation follows:
[tex]C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O[/tex]
By the stoichiometry of the reaction:
If 1 mole of pentane produces 6 moles of water
So, 0.250 moles of pentane will produce = [tex]\frac{6}{1}\times 0.250=1.5mol[/tex] of water
Molar mass of water = 18 g/mol
Plugging values in equation 1:
[tex]\text{Mass of water}=(1.5mol\times 18g/mol)=27g[/tex]
Hence, the mass of water produced is 27 g
A doctor is testing a new medication and he doesn’t tell the people in the study about the possible side effects of the medicine. He is _____.
why do objects cool down
Answer:
wla dyan ang sagut ehh baka mali yan
WHAT IS THE STOCK NAME FOR FeSO^3
How many moles of oxygen are required to react with methanol in order to produce 13 moles of formaldehyde?
Answer:
6.5 moles of Oxygen are required
Explanation:
Based on the reaction:
CH3OH + 1/2 O2 → CH2O + H2O
1 mole of methanol reacts with 1/2 moles O2 to produce 1 mole of formaldehyde and 1 mole of water.
Thus, to produe 13 moles of formaldehyde, CH2O, are needed:
13 moles CH2O * (1/2mol O2 / 1mol CH2O) =
6.5 moles of Oxygen are requiredexplain how ships made of steel float on water
Answer:
The air that is inside a ship is much less dense than water. That's what keeps it floating
Which of the following statements regarding carbon is false? Group of answer choices Carbon has the capacity to form single and double bonds. Carbon has the ability to bond with up to six other atoms. Carbon has a tendency to form covalent bonds. Carbon has the ability to bond together to form extensive branched or unbranched "carbon skeletons."
Answer: The statement, carbon has the ability to bond with up to six other atoms is false.
Explanation:
Carbon is a group 14 element and it is a non-metal. The atomic number of carbon is 6 and its electronic distribution is 2, 4.
This means that there are 4 valence electrons present in it. Also, in order to attain stability a carbon atom forms only covalent bonds, that is, it shares its valence electrons with its own atoms or atoms of other elements.
Carbon has the capacity to form single and double bonds.
As valency of carbon is four so it can only combine to 4 other atoms vis single bond and it cannot bond with up to six other atoms.
Carbon shows the property of catenation, that is, it forms covalent bonds with its own atoms in a large number. So, carbon has the ability to bond together to form extensive branched or unbranched "carbon skeletons".
Thus, we can conclude that the statement, carbon has the ability to bond with up to six other atoms is false.
3KOH + FeCl3 → Fe(OH)3 + 3KCl
How many grams of KCl are produced when 12.5 moles of KOH completely react with excess of FeCl3?
Answer:
sry, dk
Explanation:
Identifying Changes of Matter
Which of these are chemical changes in matter? Check all tha
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
How many liters of hydrogen (at 0.97atm and 24c) will produce 180 grams of water
I also need to know how to get the answer.
H₂ + ½O₂ → H₂O
2g → 18g
So, 18g water needs 2g H₂
So, 1g water needs 2/18g H₂
So, 180g water needs 2/18 x 180g H₂
→ 20 litres of H₂
Answer:
Explanation:
Molar mass of water, H2O = 2 + 16 = 18
So 180g of water contains 10M
H2 + O -> H2O
10M of Hydrogen is needed to produce 10M of water.
Molar volume at STP = 22.4L
So 10M of Hydrogen at STP = 224L
With Ideal Gas Law, P1V1/T1 = P2V2/T2
At STP, P1 = 1atm, T1=273K
At 0.97atm and 24c (273+24 = 297K), 10M of Hydrogen will take up:
1*224/273 = 0.97*V2/297
V2 = 224*297/273/0.97
= 251.23L
So the answer is 251.23L
PLEASE HELP : Arrange the following elements into a food chain: plants, snake, Sun, hawk, and mouse.
Answer:
Plants ➯ Mouse ➯ Snake ➯ Hawk ➯ Sun
Explanation:
In Order As A Food Chain
The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.
What is element?A substance that could not be further decomposed according to any chemical reaction is known as a chemical element.
What is food chain?
The flow of nutrients as well as energy through such an ecosystem is described by a food chain. Energy is first produced by plants at the most fundamental level, and then it is used by higher-level species like herbivores. Energy is then transmitted from one carnivore to the next when they eat the herbivores.
The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.
To know more about food chain and element
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An apple has been left out, and it is starting to rot. Which of the following is the best method to slow down the chemical changes that are occurring?
The best method is to keep rinsing the apple with water every hour.
The best method is to keep the apple in a cooler place.
The best method is to put the apple in the sun to warm it up.
The best method is to wrap the apple in plastic.
Help!! Please explain how you get the answer
Answer:
5 moles
Explanation:
First, write out the balanced equation:
2Al + Fe₂O₃ → Al₂O₃ + 2Fe
Reaction ratio of Al to Fe₂O₃ is:
2 : 1
This means 2 moles of Al will react with 1 mole of Fe₂O₃
Al: 5 mol
Fe₂O₃: 3 mol
Multiply the reaction to get moles of both reactants you have:
2 : 1 (×⁵/₂) = 5 : ⁵/₂
2 : 1 (×3) = 6 : 3
In other words, 5 moles of Al will react with ⁵/₂ moles of Fe₂O₃;
And 3 moles of Fe₂O₃ will react with 6 moles of Al;
But, we do not have 6 moles of Al, therefore only the 5 moles of Al available will react;
5 moles of Al reacts with ⁵/₂ moles of Fe₂O₃, as we can see from the ratios we calculated above, the remaining ¹/₂ mole of Fe₂O₃ will not react;
We say that Al is the limiting reactant because all the Al will react but all the Fe₂O₃ does not (i.e. it is in excess);
Next and last, the reaction ratio of Al to Fe is:
2 : 2 or, more simply 1 : 1
This means the moles of Al that reacts is the equal to the moles of Fe produced from the reaction;
We've established that 5 moles of Al will react with ⁵/₂ moles of Fe₂O₃, so 5 moles of Fe will also be produced (since the ratio is 1 : 1);
You could also work this out using the moles of Fe₂O₃ that react;
The reaction ratio of Fe₂O₃ to Fe:
1 : 2
So the moles of Fe produced is 2× the moles of Fe₂O₃;
If ⁵/₂ moles of Fe₂O₃ reacts, then simply multiply this by 2 which is 5 moles
Chloe’s teacher gives her and her lab partner soil samples from different parts of the city: the park, the area next to a pond, the school, and a neighborhood. Chloe’s teacher also gives her a soil tester kit, which determines the pH of the soil. Chloe and her lab partner need to determine the pH of each soil sample and then compare them.
Fill in the blank with the word that best completes the statement.
This investigation is a(an)______investigation.
Answer:
an
Explanation:
It is AN because investigation starts with I ( i is a vowel). When there are vowels we use An.
Pls mark me brainliest!
Question 14 of 30
Which of the following elements has 1 valence electron?
The Periodic Table
A. Sodium (Na)
B. Chlorine (CI)
C. Calcium (Ca)
D. Helium (He)
SUBMIT
Answer:
A. Sodium (Na)
Explanation:
The total number of electrons in the outermost principal energy level of an element is called the valence electrons of that element.
Na (11)---→1s2 2s2 2p6 3s1
There 1 electron in the outermost principal energy level of Sodium. So, the number of valence electron of Sodium is 11.
Answer:
Na
Explanation:
I was learning about it recently, that dude's right, it's Sodium
Explain how monumentum conservation is applied in ball games
Answer:
Hi , your answer is that At impact, the cue ball stops, but transfers all of its momentum and kinetic energy to the other ball, resulting in the hit ball rolling with the initial speed of the cue ball. In an inelastic collision, momentum is conserved, but the total kinetic energy of the system is not conserved
Explanation:
i really hope i helped , pleae give me brainliest , have a nice day and thank you in advance :) .
Question 1 of 30
Why does atomic size increase as you go down a group on the periodic table?
A. Because the number of electron shells increases
B. Because there is more total attraction between electrons in the
shells and protons in the nucleus
C. Because the number of electron shells decreases
D. Because there is less total attraction between electrons in the
shells and protons in the nucleus
SUBMI
Answer:
Explanation:
Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.
What happens to the freezing point of a solution when more solute is added?
In relation to the reactants of a chemical reaction, the products are
Answer:
the products are the substances made after the chemical reaction has happened
Explanation:
does salt affect the boiling time of water?
Answer:
Yes
Explanation:
Yes, but almost insignificantly. The regular boiling point of water is 100 degrees celcius, adding a small handfull of salt will increase the boiling point to roughly 100.04 degrees celcius. Therefore, it is almost insignificant but still does affect it. This is mainly because salt changes the way the molecules react thus making it harder for them to change state from liquid to gas. This ultimately causes the water to get hotter before boiling actually occurs.
