Answer:
343 meters per second
Explanation:
How does a scientist answer a scientific question? A. By observing and measuring B. By asking others for their opinions C. By finding the answer in a book D. By guessing the right answer
Answer:
The answer is A
Explanation:
Because . . .
- A is correct because scientist make their statements by using their observations and tools to measure.
- B is incorrect people's opinions are not facts! Plus, opinions can be wrong.
- C is incorrect because that book can be outdated and not every answer is in a book.
- D is absolutely incorrect because guessing a "right" answer can be wrong. For example, if you were a scientist and you guessed a treatment for coronavirus, you will defiantly get fired because you don't have evidence or logic to back up your answer. In addition, if people used ur "treatment" the one you have guessed as the "right" answer, you can put people's lives in danger and they can possibly die. You will defiantly be responsible for it and be put into jail.
Answer:A
Explanation:
Determine the overall energy change for the reaction between hydrogen and oxygen shown in Question 13. Use Figure 2.
Answer:
–500KJ
Explanation:
Data obtained from the question include the following:
Heat of reactant (Hr) = 800KJ
Heat of product (Hp) = 300KJ
Enthalphy change (ΔH) =..?
The enthalphy change is simply defined as the difference between the heat of product and the heat of reactant i.e
Enthalphy change = Heat of product – Heat of reactant
ΔH = Hp – Hr
With the above formula, we can easily calculate the enthalphy change as follow
ΔH = Hp – Hr
ΔH = 300 – 800
ΔH = –500KJ.
Therefore, the overall energy change for the reaction between hydrogen and oxygen shown in the diagram above is –500KJ
This turbine was mostly installed because wind power ?.......
Answer:
Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.
Explanation:
Answer:
Explanation:
It was installed to help with the electricty in europe
For the acids, use the formula pH = -log[H+). (Because HCl has 1 H+ ion per formula unit, [H+] equals the
molarity.) For water, use what you know about the pH of neutral solutions. For the bases, examine and
extend the pattern. DONE
0.1 M
НСІ
0.001 M
НСІ
0.00001 M
НСІ
Distilled
Water
0.00001 M
NaOH
0.001 M
NaOH
0.1 M
NaOH
pH
pH:
pH:
pH: 7
pH:
pH:
pH:
Answer:
pH = 1
pH = 3
pH = 5
pH = 9
pH = 11
pH = 13
Explanation:
The pH is defined as log [H⁺]. HCl in solution produce H⁺. That means HCl concentration is equal to H⁺ concentration. Thus:
- 0.1M HCl. pH = -log 0.1 = 1
- 0.001M HCl. pH = -log 0.001 = 3
- 0.00001M HCl. pH = -log 0.00001 = 5
For a base that produce OH⁻ in solution you can define a pOH as pOH = -log [OH⁻] knowing (For water equilibrium) pH = 14 - pOH
Thus, for the NaOH solutions:
- 0.00001M NaOH: pOH = -log 0.00001M = 5. pH = 14 - 5 = 9
- 0.001M NaOH: pOH = -log 0.001M = 3. pH = 14 - 3 = 11
- 0.00001M NaOH: pOH = -log 0.1M = 1. pH = 14 - 1 = 13
Answer:
pH = 1
pH = 3
pH = 5
pH= 7
pH = 9
pH = 11
pH = 13
Explanation:
Just did the test :)
what is (9c/-9)/-3 in simplified form
Answer:
Thus, simplified form of (9c/-9)/-3 is c/3.
Explanation:
we have to get (9c/-9)/-3 in simplified form
let simplify (9c/-9)
(9c/-9) = -c as 9/9 gets cancelled
now using value of (9c/-9) as -c and putting it in (9c/-9)/-3. we have given below equation
-c/-3 - sign is both in numerator and denominator hence it gets cancelled
-c/-3 = c/3
Thus, simplified form of (9c/-9)/-3 is c/3.
Answer
c/3
Explanation:
9c/-9 = -c
-c/-3 = c/3
GIVE BRAINLIEST PLS
What defines an exothermic reaction?
O A. A reaction that needs heat added
O B. A reaction that possesses enthalpy
O c. A reaction that relies on collisions
O D. A reaction that produces heat
a reaction that produce heat
Answer:
A reaction that produces heat.
Explanation:
formula of an exothermic reaction
Reactants → Products + Energy
WILL MARK BRAINLIEST AND 20 POINTS!!!!
Iguanas need to live in a habitat that is very warm, so the pet store warms their enclosures with “basking lights” which act as an artificial sun. Describe how the three methods of thermal energy transfer may take place within the iguana’s enclosure.
Answer:
Heat can travel from one place to another in three ways: Conduction, Convection and Radiation. Both conduction and convection require matter to transfer heat. Conduction is the transfer of heat between substances that are in direct contact with each other. Thermal energy is transferred from hot places to cold places by convection. Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object as is the case with conduction and convection. Heat can be transmitted through empty space by thermal radiation often called infrared radiation.
The thermal energy transfer may take place within the iguana’s enclosure through Conduction, Convection, and Radiation.
What are Conduction, Convection, and Radiation?In conduction, heat transfer happens between objects by direct contact. If the heat transfer takes within the fluid then it is In convection. In radiation, heat transfers without involving particles through electromagnetic waves.
In conduction, Heat transfer occurs because of the difference in temperature. In convection, heat transfer occurs due to the difference in density. In radiation, heat transfer occurs with a temperature greater than 0 K in all objects.
In convection, heat transfer in conduction is slow while in convection, heat transfer, in convection is faster and in radiation, the heat transfer in radiation is the fastest.
Conduction and convection heat transfer does not follow the law of refraction and reflection. Radiation heat transfer follows the law of refraction and reflection.
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which of the following elements would you expect to behave most like magnesium?
a) sodium
b) calcium
c) aluminum
d) scandium
The element that would behave most likely magnesium is calcium. The correct option is b.
What is an element?An element is a material whose atoms all contain the same number of protons: that is, all atoms of each element have the same amount of protons.
Elements are the most basic chemical forms and thus cannot be broken down chemically.
A chemical element is something that cannot be broken down further through any chemical reaction. Every element's atom encompasses a distinct number of protons.
A pure element is defined in chemistry as a substance whose atoms all (or almost all) have the same atomic number, or number of protons.
Beryllium and Calcium exhibit chemical reactions similar to Magnesium.
Thus, the correct option is b.
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How much energy is required to raise the temperature of 2 kg of iron from
20°C to 23°C? (Refer to table of specific heat values.)
O A. 2.7 J
O B. 900 J
O c. 2700 j
O D. 1.35
Answer:
252000j
Explanation:
Heat lost= heat gained
4200×2×3=heat lost
Energy =25200j
Answer: 2700 j
Explanation:
Q (energy) = m (mass) * t (change in temp) * c (specific heat capacity)
Plug in the values...
Q = 2(3)(0.45) (specific heat capacity of iron)
Q = 2.7 Kj
convert kilo joules to joules and you get 2700 j
Hope this helps :)
Given:
N2 + 3H2 → 2NH3
In the chemical reaction, how many grams of nitrogen are needed to completely react with 24.3 grams of hydrogen? Use the periodic table to get the weights of the elements.
Drag each number to the correct location to complete the analysis.
Answer:
113.4g of N2
Explanation:
Step 1:
The balanced equation for the reaction.
N2 + 3H2 —> 2NH3
Step 2:
Determination of the mass of N2 and H2 that reacted from the balanced equation. This is illustrated below:
Molar mass of N2 = 2x14 = 28g/mol
Mass of N2 from the balanced equation = 1 x 28 = 28g
Molar mass of H2 = 2x1 = 2g/mol
Mass of H2 from the balanced equation = 3 x 2 = 6g
From the balanced equation above, 28g of N2 reacted with 6g of H2.
Step 3:
Determination of the mass N2 required to react with 24.3g of H2.
The mass of N2 required to react with 24.3g of H2 can be obtained as follow:
From the balanced equation above, 28g of N2 reacted with 6g of H2.
Therefore, Xg of N2 will react 24.3g of H2 i.e
Xg of N2 = (28 x 24.3)/6
Xg of N2 = 113.4g
Therefore, 113.4g of N2 is required to react completely with 24.3g of H2.
24.3g H2 × 1 mol H2/2.016g H2 × 1 mol N2/3 mol H2 × 28.014 g N2/1 mol N2 = 113g N2
Given the balanced equation: Pb(NO₃)₂(aq) + 2NaCl(aq) ➔ PbCl₂(s) + 2NaNO₃(aq). What type of reaction is represented by this equation
Answer: The given reaction is a double displacement reaction.
Explanation:
A chemical reaction in which two different compounds chemically react with each other by switching places of both positive and negative ions is known as a double displacement reaction.
For example, [tex]Pb(NO_3)_2(aq) + 2NaCl(aq) \rightarrow PbCl_2(s) + 2NaNO_3(aq)[/tex]
Here, both [tex]Pb^{2+}[/tex] and [tex]Na^{+}[/tex] ions switched places. Also, both [tex](NO_3)^{-}_{2}[/tex] and [tex]Cl^{-}[/tex] ions switched places.
Therefore, we can conclude that the given reaction is a double displacement reaction.
The dust and gas found between stars is called quasars. t or f
Answer:
The statement is false.
Explanation:
Quasars are astronomical objects that are very luminous found in the centres of dome galaxies and powered by gas spiraling at high velocity into an extremely large black hole. However, Nebula/Nebulae is a giant cloud of dust, hydrogen, helium and other ionized gases found in space. It is sometimes called "star nurseries"
I hope this helps you :)
1.46 g H2 is allowed to react with 10.5 g N2, producing 2.72 g NH3. What is the theoretical yield in grams for this reaction under the given conditions?
Express your answer to three significant figures and include the appropriate units.
Answer : The theoretical yield in grams for this reaction under the given conditions is, 8.28 grams.
Explanation : Given,
Mass of [tex]H_2[/tex] = 1.46 g
Mass of [tex]N_2[/tex] = 10.5 g
Molar mass of [tex]H_2[/tex] = 2 g/mol
Molar mass of [tex]N_2[/tex] = 28 g/mol
First we have to calculate the moles of [tex]H_2[/tex] and [tex]N_2[/tex].
[tex]\text{Moles of }H_2=\frac{\text{Given mass }H_2}{\text{Molar mass }H_2}[/tex]
[tex]\text{Moles of }H_2=\frac{1.46g}{2g/mol}=0.73mol[/tex]
and,
[tex]\text{Moles of }N_2=\frac{\text{Given mass }N_2}{\text{Molar mass }N_2}[/tex]
[tex]\text{Moles of }N_2=\frac{10.5g}{28g/mol}=0.375mol[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical equation is:
[tex]3H_2+N_2\rightarrow 2NH_3[/tex]
From the balanced reaction we conclude that
As, 3 mole of [tex]H_2[/tex] react with 1 mole of [tex]N_2[/tex]
So, 0.73 moles of [tex]H_2[/tex] react with [tex]\frac{0.73}{3}=0.243[/tex] moles of [tex]N_2[/tex]
From this we conclude that, [tex]N_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]H_2[/tex] is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of [tex]NH_3[/tex]
From the reaction, we conclude that
As, 3 mole of [tex]H_2[/tex] react to give 2 mole of [tex]NH_3[/tex]
So, 0.73 mole of [tex]H_2[/tex] react to give [tex]\frac{2}{3}\times 0.73=0.487[/tex] mole of [tex]NH_3[/tex]
Now we have to calculate the mass of [tex]NH_3[/tex]
[tex]\text{ Mass of }NH_3=\text{ Moles of }NH_3\times \text{ Molar mass of }NH_3[/tex]
Molar mass of [tex]NH_3[/tex] = 17 g/mole
[tex]\text{ Mass of }NH_3=(0.487moles)\times (17g/mole)=8.28g[/tex]
Therefore, the theoretical yield in grams for this reaction under the given conditions is, 8.28 grams.
How many moles are in 27.10 g of potassium (K)?
Answer: 0.701 mol K
Explanation:
To find the number of moles in 21.10 g of K, we would need to know the molar mass of K.
K=30.098 g/mol
We would divide 27.10 moles by the molar mass to find how many moles of K are in 27.10 g.
[tex]21.10g*\frac{1mol}{30.098g} =0.701 mol[/tex]
What is a saturated solution? A. A solution containing more solute than should be possible. B. A solution that can still dissolve more solute. C. A solution that cannot dissolve any more solute. D. A solution that is not able to dissolve any of the solute.
Answer:
C. A solution that cannot dissolve any more solute.
Explanation:
hope it helps .
Answer:
The correct answer is C. A solution that cannot dissolve any more solute.
Explanation:
How does water's dissolving power support life on Earth?
2012 Gynnin
Can you measure tenths of a gram with confidence using this balance?
yes
no
Yes
The accuracy to which we can measure a value using a given instrument is dependent on the instrument's least count. The least count of this instrument is 0.1 grams, or a tenth of a gram. Therefore, we may measure to the tenth of a gram with confidence. We cannot measure to the hundredth of a gram however.
Blue eyes are recessive. Jonathan is hybrid for blue eyes. His wife Carly, has blue eyes. If they have four children, how many will have blue eyes?
1
2
3
4
Answer:
possibly two
Explanation:
you said Jonathan had hybrid eyes, did you mean that he was heterozygous? if so 2 out of 4 will have the recessive gene "blue".
hafnium: atomic number
atomic number 15
atomic number 45
osmium: atomic number
magnesium: atomic number
The question is incomplete. The complete question is as follows:
Use the periodic table to identify the name or atomic number for each element below. (Give the name, not the chemical symbol, for each element.)
hafnium: atomic number
atomic number 15
atomic number 45
osmium: atomic number
magnesium: atomic number
Answer:
hafnium: atomic number - 72
atomic number 15 - Phosphorus
atomic number 45 - Rhodium
osmium: atomic number - 76
magnesium: atomic number - 12
Explanation:
A Periodic table is a tabular representation of elements or atoms arranged on the basis of their atomic number and atomic mass.
So according to the periodic table:
Hafnium is metal and atomic number of hafnium is 72 that lies in group 4 (IVb) of the periodic table.Atomic number 15 in the periodic table represents Phosphorus with the symbol P.Atomic number 45 in the periodic table represents Rhodium with symbol Rh.Atomic number of osmium is 76 that lies in Group 8 (VIIIB) of the periodic table.Atomic number of magnesium is 12 that lies in group 2 (II) of the periodic table.Hence, the correct answer is:
hafnium: atomic number - 72
atomic number 15 - Phosphorus
atomic number 45 - Rhodium
osmium: atomic number - 76
magnesium: atomic number - 12
Why is water necessary for life
Answer:
Water is necessary for life because water carries nutrients to all of our cells. Water also carries oxygen to the brain and allows our body to absorb minerals and vitamins
Explanation:
hope this helps! good luck :)
Goals of sustainable development include
Select one:
O a. protecting the environment.
O b. helping people get out of poverty.
c. using resources only as quickly as they are replaced.
O d. all of these.
Answer:
I am gonna say d all of the above
Explanation:
I may be wrong sorry
The reaction, C2H6) (l) + 3)2 (g) produces 2CO2 (g) + 3H2) (g), is the combustion of ethanol. What occurs as the reaction proceeds.
Answer:
So as the reaction proceeds we lose energy as the reaction is exothermic due to the delta H being negative, this shows that heat flows from the system to its surroundings.
Explanation:
2H6O (l) + 3O2 (g) = 2CO2 (g) + 3H2O (g)
2CH3CH2OH(l) + 3O2(g) = 2CO2(g) + 3H2O(g) ΔH = -1234.8kJ/mol
I'm pretty sure this is what your equation is supposed to be, seems to be an error where you've pasted it and it's replaced the O's with )
So as the reaction proceeds we lose energy as the reaction is exothermic due to the delta H being negative, this shows that heat flows from the system to its surroundings.
Can anyone help need answer asap
Answer:
Rises, sinks
the correct answer is B
Answer:
rises, sinks
Explanation:
Hot magma rises because as the temperature increases, it expands and becomes less dense. As it reaches the top, it cools down and becomes more dense, which means it will sink. Therefore, hot magma rises and cool magma sinks in convection mantle mechanism.
What is the molarity of a solution of HCI if 3 moles dissolved in 2.5 liters of water?
Answer:
1.2 mol/L
Explanation:
Molarity = mol solute/L solution
We can accept that
L solution = L water = 2.5 L.
Molarity = 3 mol/2.5 L = 1.2 mol/L
1.2 mol/L is the molarity of a solution of HCl if 3 moles dissolved in 2.5 liters of water.
MolarityMolarity (M) is defined as the number of moles of solute dissolved in 1 L of solution. Molarity is also known as Molar concentration. The S.I Unit of Molarity is molar (M) or mol/L.
How to find molarity of a solution ?Molarity (M) = [tex]\frac{\text{Mass of solute}}{\text{Volume in liters}}[/tex]
= [tex]\frac{3\ mol}{2.5\ L}[/tex]
= 1.2 mol/L
Thus, we can say that 1.2 mol/L is the molarity of a solution of HCl if 3 moles dissolved in 2.5 liters of water.
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all but one is a method of passve transport in cells
osmosis
sodium/potassium pump
facilitated transport
Answer:
The answer is Osmosis........
Answer:
osmosis
Explanation:
osmosis is a method of passive transport in cells. osmosis in passive transport cells is of water
2
The ware function
of
the particle is normalized. why?
Answer:
The probability of finding the particle somewhere in the universe must be equal to 1.
In Rutherford's gold foil experiment, most alpha particles passed through the gold foil without deflection and were detected on the screen. What caused the particles to pass through without any deflection? A. a large area of positively charged particles present in the gold foil. B. the extremely high speed of the alpha particles passing through the gold foil. C. a small area of negatively charged particles present in the gold foil. D. empty space in the atoms present in the gold foil.
Answer:
Option D.
Explanation:
Some of the alpha particles Rutherford shot at the gold foil bounced back, some scattered; but the majority of them went right through. That meant there had to be some sort of positively charged subatomic particle in there that pulled them through, but it had to be at the center and couldn't take up a lot of room.
Identify which element this particle is and write its symbol, including charge?
1) particles: x
neutrons: 4
Protons: 3
electrons:3
2) particles: Y
Neutrons:5
Protons:4
Electrons:4
3) particles: Z
Neutrons: 6
Protons: 6
Electrons: 6
4) particles: A
Neutrons: 6
Protons: 4
Electrons: 2
Answer:
Explanation:
1. lithium=Li
2.berilium=Be
3.carbon=C
4.Lithium= Li1+
The elements with their symbols and charge are:
1. Lithium, Li, charge is 1.
2. Beryllium, Be, charge is 2+
3. Carbon, C
4. Lithium, Li, charge is 1+
What are chemical elements?Chemical elements are the base of everything present on the Earth. These elements are present under the earth.
There are 118 elements traced and are present in either free or mixed form.
Thus, the correct options are 1. Lithium, Li, charge is 1.
2. Beryllium, Be, charge is 2+
3. Carbon, C
4. Lithium, Li, charge is 1+
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One of the primary benefits of a survey is that they
A. can generate cause-and-effect conclusions
B. allow efficient gathering of unobservable phenomena
C. allow for researchers to observe one's natural behavior
D. are able to provide a detailed look at a single subject
Answer:
B). Allow efficient gathering of unobservable phenomena.
Explanation:
Surveys are described as the method of gathering information from a specified group of respondents for purposes like research or assessment of the truth of thoughts or opinions associated with a process.
As per the question, one of the most considerable benefits of the survey is that 'it allows the efficient gathering of unobservable phenomena'. The data associated with phenomena like stated preferences, behaviors, beliefs, and factual information are unobservable and can not be collected through observation but surveys help in doing so as well as in the assessment of the validity or reliability of the existing propositions about such phenomena. Thus, option B is the correct answer.
Answer: b
Explanation:
1.What are pollen grain? 2. what is an embryo?
Answer: 2= baby being developed= embryo 1 i dont know sorry
Explanation:
Answer:
Pollen grains is the Male reproductive organ.
An embryo is a zygote.
Explanation: