Answer:
Expiremental group for -first one. Second one-2
Explanation:
I Had Those QuestIons On mY tEsttt!!
scientists studying squirrels in a forest observed that the squirrel population decrease over a period of five years. which statement is the most likely explanation for the decrease in the population?
Answer:
1.An increment of predators
2.unavailability of food resources due to change in climate causing famine
3.Spread of diseases over time that might kill the squirrels
4.An increment of squirrels which caused high competition on food,thus some of them had to migrate
5.Might be fire break out over some time that caused death to some squirrels in the reasoning of the period of time
Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Im very loss with this question
Percent yield of water : 70%
Further explanationReaction
2H₂ (g) + O₂ (g) → 2H₂O (g)
mol H₂(MW= 2 g/mol) :
[tex]\tt \dfrac{13.8~g}{2~g/mol}=6.9~mol[/tex]
mol H₂O = mol H₂ = 6.9
mass H₂O(theoretical) :
[tex]\tt 6.9\times 18~g/mol=124.2~g[/tex]
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\\%yield=\dfrac{87}{124.2}\times 100\%=70\%[/tex]
Carbon dioxide is formed by the given formula.
C(s)+O2(g)→CO2(g)
Carbon dioxide is
A
a compound of two elements, carbon and oxygen.
B
a mixture of two compounds, carbon and oxygen.
C
a compound of two atoms, carbon and oxygen.
D
an element of two atoms, carbon and oxygen.
Answer:
A
Explanation:
How does a longshore current change the beach
Answer:
As this sheet of water moves on and off the beach, it can “capture” and transport beach sediment back out to sea. This process, known as “longshore drift,” can cause significant beach erosion.
Someone answer these please! It’s multiple choice
Answer: Number 1 is titanium.
The one where you calculate a tin block is 13.0cm.
3. Is A) Same Density And Same Chemical Properties.
4. Is also A. Ne
Explanation:
. The model shows Earth in several positions relative to the Sun. In which position is it winter in North America?
Which of these describes a challenge that the engineer of a high-altitude
airplane would need to consider?
A. More fuel is used at higher altitudes.
B. The airplane may succumb to the power of gravity as lift
decreases at higher altitudes.
C. The airplane may need a heat shield for protection from sonic
booms.
O D. The airplane will create more drag at higher altitudes than lower
altitudes.
Answer:
I think its (B)
Explanation:
as when the air thins out at higher elevations, your lift decreases so at some point, the plane cant produce enough lift to overcome gravity.
What does the symbol △ in a chemical equation mean?
Answer:
Delta, or subject to change.
Explanation:
Δ→ triangle indicates that the reaction is being heated.
What is a chemical equation?Chemical equations are symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae.
To express heating, we usually use Δ over reaction arrows like:
[tex]CaCO_ 3[/tex]. Δ → [tex]CaO+O_2.[/tex]
Learn more about the chemical equation here:
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what phenomenon occurs after mass extinction?
Answer:
Diversification and adaptive radiation.
Explanation:
What is an atomic nucleus
Answer:
The atomic nucleus is the small, dense region consisting of protons and net at the center of an atom.
Explanation:
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. ... Protons and neutrons are bound together to form a nucleus by the nuclear force.
Answer:
The atomic nucleus is the small , dense region consisting of protons and neutrons at the center of an atom .
First person to comment there crush name get brainlyest
Answer:
:0
Explanation:
David <3
why do the Noble gases have the highest ionization energies across a period?
Answer:
ionization energy decreases from top to bottom in groups, and increases from left to right across a period. So technically, the noble games have the largest ionization energy.
Explanation:
Why are the Galápagos Islands such a place of interest to the world
Answer:
Explanation:
first to answer correctly gets brainleist! (you dont needa hear that vid thingy tahts just for ppl who cant read or need orial commidations or wtv lol)
Answer:
The seasons are a result of the tilt of the earth
Can somebody help me with this??!
What do radio waves and microwaves have in common?
Both are at the side of the spectrum that has the lowest frequency.
Both are found next to visible light on the electromagnetic spectrum.
Both are at the side of the spectrum that has the highest radiant energy.
Both are at the side of the spectrum that has the shortest wavelengths.
Answer:
Both are at the side of the spectrum that has the lowest frequency.
Explanation:
i took the test
Answer:
a
Explanation:
did i do this correctly? someone please help and if i'm incorrect please give me the right answer!
Answer:
I think It is correct
I may be wrong but that is just what I think...sorry if I am wrong
What makes the element oxygen different from the element hydrogen?
Answer: the difference is due to the fact that one water molecule has two hydrogen atoms to one oxygen this means it takes two water molecules (2 H2O) to make one oxygen molecule (02) .At the same time however two molecules of water (2 H20) can make two molecules of hydrogen (2 H20)
Explanation: hope this helped and mark me as brainliest please =)
As water is cooled, its density increases until it reaches about
A. 4°C
B. 25°C
C. O'C
D. -2°C
The density of copper is 8.9 g/mL. What is the volume of 20.5 g copper?
Answer:
density = 8.9 g/ml
m = 20.5 g
V = ... ?
density = m/V
V = m / density
= 20.5 / 8.9
= 2.30337 ml
In a chemical reaction, what happens to the total number of each type of atom?
A
The total number of each type of atom always stays the same.
B
The total number of each type of atom either increases or decreases.
C
The total number of each type of atom always increases.
D
The total number of each type of atom always decreases.
Answer:
A
Explanation:
The total number of each type of atom always stay the same.
As a result of the Law of Conservation of Mass, during a chemical change the mass of the
products are equal to the mass of the:
A. particles
B. elements
C. reactants
D. compounds
Answer:
D. Reactants.
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
Which indicates how evidence of climate change supports the theory of continental drift?
coal fields in several continents
volcano formation
glacial evidence found in South America
folded mountains in Africa and South America
Glacial evidence found in South America, do indicate how evidence of climate change has supports the theory of continental drift.
Climate change occurs daily all over the world. This is largely due to man's activities that has affected the atmosphere and the earth.Continental drift is simply known as the theory that states that the continents at a time has formed a single landmass, broke up, and drifted to their present locations. Glacial evidence in South America has made man to believe more in the continental drift hypothesis.Conclusively, we can therefore say that Glacial evidence found in South America, do indicate how evidence of climate change has supports the theory of continental drift.
Learn more from
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Answer:
glacial evidence found in South America
Explanation:
Which of the following describes the energy transformations that occur when a toaster is used to make toast?
Thermal energy is transformed into chemical energy in the toaster, and chemical energy is transformed into thermal energy in the toast.
Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast.
Light energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.
Electrical energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.
Answer:
Thermal energy (B)
Explanation:
just did it
Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.
What is chemical energy?Chemical energy is defined as chemical substances' potential energy, which is released as they experience chemical reactions and change into other substances. Additionally, it is what binds a substance's molecule's together. The body transforms or changes the chemical energy in food into heat and mechanical motion.
The wire attached to the power source transmits electrical energy to the toaster. The heating element is a part of the toaster. This heating element transforms electrical energy into heat energy, which aids in toast preparation, when it comes into contact with it. Thus, with an electric toaster, electrical energy is converted to heat energy.
Thus, electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.
To learn more about chemical energy, refer to the link below:
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Can someone tell me about kinetic, potential, and gravitational energy?
Answer:
the internet can teach you alot about all 3 things
Explanation:
Answer:
if you go on YT and search kinetic, potential, and gravitational energy their will be a bill nye vid that is very informational on the topic at hand!!!
Explanation:
hope this helps!!
Which of the following are electromagnetic waves? *
Water waves
Sound waves
Radio waves
Seismic waves
answer this pls thanks
Answer: It is element nitrogen. It has an atomic number of 7 and the valence electron is 5. It needs 3 electrons to complete its octet state. That's why sometimes it has the oxidation number of -3 in ammonia.
How do you compare the theoretical and expirimental values for decomposition of ammonium nitrate?
Answer:
it decomposes into nitro oxide and water
Does the model correctly represent the electron dot diagram of magnesium? Why or why not? Check all that apply.
M g with 1 dot above and 1 right.
*{Yes, because the chemical symbol of magnesium is Mg.}
No, because the chemical symbol of magnesium is Mn.
*{Yes, because magnesium has two valence electrons.}
No, because magnesium has seven valence electrons.
No, because both of the dots should be on top of the chemical symbol
Answer 1 and 3
Answer:
1 and 3
Explanation:
Answer: A and B or 1 and 3
Explanation:
8
Calcium carbonate (limestone) decomposes when heated.
Caco, + CaO + CO2
b) Calculate the volume of carbon dioxide produced if 10 grames were decomposed.
Explanation:
Equation -
CaCO₃ → CaO + CO₂
molecular masses of -
CaCO₃ = 40+12+16×3 = 100 g/mol
CaO = 40+16 = 56 g/mol
CO₂ = 12+16×2 = 44 g/mol
Now,
If 100 g of CaCO₃ is decomposed then it produces 56 g of CaO and 44g of CO₂
Then,
If 1 g of CaCO₃ is decomposed then it produces 56/100g of CaO and 44/100g of CO₂
Now,
Here in question, 10g of CaCO₃ is decomposed
It means, It produces
56/100 × 10 = 56/10 = 5.6 g of CaO and
44/100 × 10 = 44/10 = 4.4 g of CO₂
Now,
we get that 10 g of CaCO₃ on burning produces 4.4 g of CO₂
we need to calculate volume of 4.4 g of CO₂
mole = mass/Gram molecular massThen,
mole = 4.4/44 = 0.1
Now,
volume = mole × 22.4 (in Litres)
= 0.1 × 22.4 = 2.24 L
Hence,
2.24 L of CO₂ will be produced when 10g of CaCO₃ decomposed.