by rounding them to the neerest 10
1. What is a chemical reaction
a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
Answer:
Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products
Explanation:
cells use oxygen to release energy during blank
Answer:
Cellular respiration
Answer:
cellular respiration
Explanation:
How many grams are in 657 L of N2 gas at STP?
Answer:
821.25gm
Explanation:
volume = 657
no of mole = 657/22.4
mass = no of mole * molecular mass
mass = 657/22.4*28
= 821.25gm
When does the number of electrons be greater than the number of protons?And give examples.
Answer:
This accepting atom will then become an anion. The anion has more electrons than protons. This means that some of the electrons will not be canceled out, giving the atom an overall negative charge.
If an object has more protons than electrons, then the net charge on the object is positive. If there are more electrons than protons, then the net charge on the object is negative. If there are equal numbers of protons and electrons, then the object is electrically neutral.
Explanation:
Tritium (H-3) is a radioactive isotope of hydrogen with a half-life of 12.3 years. How long would it take for a 40.0g sample to decay down to 1.25g
Answer:
the answer maybe is 61.5 years (please check with others) tq
Explanation:
40/2=20
20/2=10
10/2=5
5/2=2.5
2.5/2=1.25
so one half life is 12.3 years
then 12.3 ×5 =61 .5
(why 5 ? because it decay 5 times to get 1.25 from 20)
How many grams of MgO are in 3.500 moles?
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, lead has the highest mass. 141.05gram of MgO are in 3.500 moles.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. 141.05gram is the mass of MgO.
Mathematically, the molar mass, mole and given mass can be related as
Mole of MgO =given mass of MgO ÷ molar mass of MgO
Molar mass of MgO= 40.30 g/mol
Mole of MgO= 3.500 moles
substituting the values, we get
3.500 moles = mass of MgO÷ 40.30 g/mol
Mass of MgO=141.05gram
Therefore, 141.05gram of MgO are in 3.500 moles.
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Someone please answer this...
Answer:
5446.8 J
Explanation:
From the question given above, the following data were obtained:
Mass (M) = 50 g
Initial temperature (T₁) = 70 °C
Final temperature (T₂) = 192.4 °C
Specific heat capacity (C) = 0.89 J/gºC
Heat (Q) required =?
Next, we shall determine the change in the temperature. This can be obtained as follow:
Initial temperature (T₁) = 70 °C
Final temperature (T₂) = 192.4 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 192.4 – 70
ΔT = 122.4 °C
Finally, we shall determine the heat required to heat up the block of aluminum as follow:
Mass (M) = 50 g
Specific heat capacity (C) = 0.89 J/gºC
Change in temperature (ΔT) = 122.4 °C
Heat (Q) required =?
Q = MCΔT
Q = 50 × 0.89 × 122.4
Q = 5446.8 J
Thus, the heat required to heat up the block of aluminum is 5446.8 J
Someone help please!!!
1. What do you observe when you poor a hot into the glass
containing intant coffee?
Answer:
The water in glass turns dark brown.
This is due to diffusion where the coffee molecules move from the region of their high concentration to a region of their lower concentration in water.
Answer:
The instant coffee acts as a solute when hot water (the solvent) is poured. The instant coffee quickly dissolves and makes a solution.
Explanation:
Pls help, How is stoichiometry used to calculate amounts of substances in a chemical reaction?
Answer:
Thus, to calculate the stoichiometry by mass, the number of molecules required for each reactant is expressed in moles and multiplied by the molar mass of each to give the mass of each reactant per mole of reaction. The mass ratios can be calculated by dividing each by the total in the whole reaction.
Explanation: Stoichiometry is the field of chemistry that is concerned with the relative quantities of reactants and products in chemical reactions. For any balanced chemical reaction, whole numbers (coefficients) are used to show the quantities (generally in moles ) of both the reactants and products.
Please select the word from the list that best fits the definition
Tracks the location, movement, and amount of precipitation in storms
Please select the word from the list that best fits the definition
A. radar
B. satellite
Answer:
satellite
Explanation:
found it on the internet
The correct answer is Radar
What is the conversion for 5 g + 3.3 mL =
Answer:
9 g/ml
Explanation:
5 + 3.3 = 8.5
But you should use sig figs.
5 has no tenths, hundredths, and etc.
Therefore the 8.5 rounds up to 9
So the answer is 9.
2. Just like the N and S poles on bar
magnets, electrons and protons
each other.
A. attract
B. repel
C. repulse
D. push apart
Answer:
A) attract
Explanation:
hope it helps you
To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option A.
What is atom?Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.
In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. Just like the N and S poles on bar magnets, electrons and protons attract each other.
Therefore, the correct option is option A.
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True or False: The moon does not have an
atmosphere, plants, animals or oceans.
Answer:
true
Explanation:
As mentioned above, the moon does not have the same composition as the Earth, and while some of the elements present on the moon are the same, this is likely because of the moon’s formation (the Giant-Impact Theory). In general, this different in composition means that the moon cannot have an atmosphere because it is not geologically active.
2. How many protons are present in the oxygen atom? *
O A. 24
O B.16
O C.8
O 0.4
What is the answer for number 2?
Answer:
It has mass but no charge.
Explanation:
The question asks to describe ONE of the subatomic particles that could be found at location X in the model, so you should think of protons and neutrons. Now all of the answers do NOT describe a proton, but the first answer describes a neutron. Neutrons have mass but no charge. Why? The neutron has two down quarks and one up quark, down quarks, have a charge of -1/3, and up quarks have a charge of +2/3. Doing the math, you'd see that (-1/3)2+2/3 is equal to a neutral charge. So a neutron WILL have a mass, but will NOT have a charge, as they are used to hold the nucleus together.
Answer:
the last one
Explanation:
Why Do Some Things Stop While Others Keep Going?
Answer:because they run out of energy when it is transferred and to other objects, or their kinetic energy
Explanation:
when you burn wood in a campfire, ____ energy is converted to ____ and light energy.
Answer:
when you burn wood in a campfire, chemical energy is converted to heat and light energy.
Explanation :
When wood is burned stored potential energy ( in the form of chemical energy ) in the log is released due to heating by other excited atoms . This process is called combustion and requires presence of oxygen. So, combustion can be defined as a process which changes chemical energy into kinetic energy in the form of heat. In case of combustion an organic say wood in this case combines with oxygen present in the atmosphere to give off carbon dioxide, water and energy in the form of heat and light .
What does a dam generating electricity from water flowing downhill show?
how systems take advantage of energy flowing from low to high
how systems take advantage of energy flowing from high to low
how systems violate the law of the second law of thermodynamics
Answer: the 3 one
Explanation: i just know
Answer:
how systems violate the law of the second law of thermodynamics
Explanation:
i had to take this quiz it is the right answer..
When 3243. grams of iron (III) chloride are reacted with 511.8 grams of hydrosulfuric acid, which is the limiting reactant?
2 FeCl3 + 3 H2S -----> Fe2S3 + 6 HCl
Answer:
Hydrosulfuric acid will act as limiting reactant.
Explanation:
Given data:
Mass of iron(III) chloride = 3243.0 g
Mass of hydrosulfuric acid = 511.8 g
Limiting reactant = ?
Solution:
Chemical equation:
2FeCl₃ + 3H₂S → Fe₂S₃ + 6HCl
Number of moles of iron(III) chloride:
Number of moles = mass/molar mass
Number of moles = 3243.0 g/ 162.2 g/mol
Number of moles = 20 mol
Number of moles of hydrosulfuric acid:
Number of moles = mass/molar mass
Number of moles = 511.8 g/ 34.1 g/mol
Number of moles = 15 mol
Now we will compare the moles of both reactant with products
FeCl₃ : Fe₂S₃
2 : 1
20 : 1/2 ×20 = 10
FeCl₃ : HCl
2 : 6
20 : 6/2 ×20 = 60
H₂S : Fe₂S₃
3 : 1
15 : 1/3 ×15 = 5
H₂S : HCl
3 : 6
15 : 6/3 ×15 = 30
Hydrosulfuric acid producing less number of moles of product thus, it will act as limiting reactant.
1. What did Henri Becquerel discover about
radiation emitted from uranium salts?
Explanation:
When Henri Becquerel investigated the newly discovered X-rays in 1896, it led to studies of how uranium salts are affected by light. By accident, he discovered that uranium salts spontaneously emit a penetrating radiation that can be registered on a photographic plate.
What is one effect of the uneven heating of Earth caused by the Sun? (Answer with a 5 sentence paragraph)
ene
(This is scinece
Answer:
Albedo
Explanation:
Usually when we talk about uneven heating of the Earth's surface we are discussing convection. The uneven heating results in some of the atmosphere to be warmer than other parts and changes in volume and pressure which result in updrafts and can cause thunderstorms and other violent weather. The cause of this is the reflectiveness of the surface of the Earth at that point (the albedo) and the angle that the sun's rays strike it at. A field covered with snow and ice is going to be much more reflective than a black top asphalt parking lot. As such the parking lot absorbs much more shortwave radiation from the sun and gets much warmer.
The uneven heating of Earth caused by the Sun craetes the difference in the atmosphere pressure and the volume of gasses present in atmosphere.
What is uneven heating of Earth?The uneven heating in the atmosphere disturbs the climatic conditions as there are some areas which are cold and some are hot then before and also changes the volume and pressure.
The change in the volume and the pressure results in the flow of the upward flow of the current air which is the main cause of thunder storm and some other climatic disaster can also happen.
Therefore, uneven heating of Earth caused by the Sun craetes the difference in the atmosphere pressure and the volume of gasses present in atmosphere.
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Which elements have two valence electrons?
A. Carbon
B. Magnesium
C. Fluorine
D. Sodium
Answer:
Magnesium
Explanation:
Magnesium is in group 2 of the periodic table. The group in which an element is found in tells us the number of valence eletrons it has.
HOPE THIS HELPED
Among the given elements, the element that have two valence electrons is Magnesium. The correct answer is option B.
Valence electrons are the electrons that are present in the outermost shell of an atom that are involved in chemical bonding. The number of valence electrons an atom has is determined by the group number it belongs to on the periodic table.
Magnesium belongs to group 2A on the periodic table, which means it has two valence electrons.
Carbon belongs to group 4A and has four valence electrons, while Fluorine belongs to group 7A and has seven valence electrons. And Sodium belongs to group 1A and has one valence electron.
Therefore, option B. Magnesium is the elements that have two valence electrons.
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Why do cat always land on their feet???
Answer:Cats’ ability to land on their feet can be chalked up to the “righting reflex” that they possess:)
Explanation:
What can help overcome a positive enthalpy of solution and allow a solid
solute to dissolve in water?
A. A decrease in entropy
B. A large amount of energy released
C. A large amount of energy absorbed
D. An increase in entropy
Answer: D. An increase in entropy
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.
For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.
To overcome a positive enthalpy of solution and allow a solid solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.
Are assorted jelly beans heterogeneous or homogeneous
Heterogeneous, which means that they are not evenly combined.
How is chemical bonding useful to our lives?
Answer:
Three types of chemical bonds are important in human physiology, because they hold together substances that are used by the body for critical aspects of homeostasis, signaling, and energy production, to name just a few important processes. These are ionic bonds, covalent bonds, and hydrogen bonds.
Explanation:
A ball, starting from rest at Position 1, rolls down and then up a curved track towards Position 5. When it reaches Position 5, it rolls back down the track
2
Which description below is most consistent with what you can expect from the ball's motion?
The ball will roll as high as Position 1 since energy cannot be created or destroyed.
The ball will roll past Position 1 since energy cannot be created or destroyed.
The ball will roll as high as Position 2 since some of the energy will be transformed to heat,
The ball will roll as high as Position 3 since that position has the least potential energy.
Kk
Answer:
D. The ball will roll as high as Position 3 since that position has the least potential energy.
Explanation:
i am not sure that it's is right or wrong
Summarize the history of radioactivity by choosing the scientist(s) involved with each discovery.
conducted experiments with uranium-containing minerals and pure uranium.
came up with the term “radioactivity.”
showed that uranium in a mineral gave off radiation even without being exposed to the Sun.
discovered radium and polonium.
conducted experiments with fluorescent minerals and photographic plates.
Answer:
Marie and Pierre CurieMarie and Pierre CurieAntoine Henri BecquerelMarie and Pierre CurieAntoine Henri BecquerelExplanation: Correct on Edg 2020/2021.
How many atoms of gold are there in 5 moles of a gold sample ?
Answer:
30.11 × 10²³ atoms
Explanation:
Given data:
Number of moles of gold = 5 mol
Number of atoms = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
5 mol × 6.022 × 10²³ atoms /1 mol
30.11 × 10²³ atoms