Answer:
C option
Explanation:
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Which concept accounts for the whole-number subscripts in chemical formulas?
A. law of multiple proportions
B. Avogadro's law
C. conservation of energy
D. conservation of matter
Answer:
Law of multiple proportions
Explanation:
When is chemical energy released
Explanation:
Chemical energy is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place. Usually, once chemical energy has been released from a substance, that substance is transformed into a completely new substance.
Answer:
Breaking or making of chemical bonds involves energy, which may be either absorbed or evolved from a chemical system. Energy that can be released or absorbed because of a reaction between a set of chemical substances is equal to the difference between the energy content of the products and the reactants, if the initial and final temperatures are the same.
Explanation:
a certain element xx has four isotopes. 51.45% of xx has a mass of 89.90470 amuamu . 11.22% of xx has a mass of 90.90565 amuamu . 17.15% of xx has a mass of 91.90504 amuamu . 20.18% of xx has a mass of 93.90632 amuamu . what is the average atomic mass of element xx ?
Considering the definition of atomic mass, isotopes and atomic mass of an element, the average atomic mass of element x is 91.16759 amu.
Definition of atomic massThe atomic mass is obtained by adding the number of protons and neutrons in a given nucleus of a chemical element.
Definition of isotopeIsotopes of the same element are those atoms where the atomic numbers are the same, but the number of neutrons is different.
Definition of atomic massThe atomic mass of an element is the weighted average mass of its natural isotopes, taking into account the relative abundance of each of them.
Atomic mass of the element in this caseIn this case, you know:
51.45% (0.5145) of x has a mass of 89.90470 amu. 11.22% (0.1122) of x has a mass of 90.90565 amu. 17.15% (0.1715) of x has a mass of 91.90504 amu. 20.18% (0.2018) of x has a mass of 93.90632 amu.Then, the average mass of the element x can be calculated as:
average mass= 89.90470 amu×0.5145 + 90.90565 amu×0.1122 + 91.90504 amu×0.1715 + 93.90632 amu×0.2018
Solving:
average mass= 91.16759 amu
Finally, the average atomic mass of element x is 91.16759 amu.
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When ionic compounds are added to water, they dissociate or break apart into ions. In the case of table salt, salt added to water dissociates into sodium ions and chloride ions. This would seem to be a chemical change. However, scientists do not consider this to be one, because the solid table salt remains after the water is evaporated. The atoms recombine into their original arrangement once the water is removed.
Which word from the selection helps you understand that physical changes can be undone?
a added
b dissociate
c recombine.
d removed
Heat that flows by conduction is the transfer of thermal energy between substances in contact. What must occur for this to happen? TA B Block A has a higher temperature than block B heat flow The two blocks are the same temperature and heat flow stops Heatis transferred from the wamer block to the cooler block 2012 Encyclopædia Batannlea, Inc. B B heat flow
Answer:
Heat is transferred from the warmer block to the cooler block
Explanation:
Heat transfer by conduction involves two or more solids. The heat generally moves from a part at higher temperature to one with a lower temperature.
Heat transfer is based on the differences in temperature profile on a body. When the temperature of the body is the same, heat is not transferred. The molecules that makes up the hotter body collides with static molecules of the cold one. Through this, heat is transferred.Acetylene torches are used for welding, but the thermite reaction can be useful in situations in which acetylene torches are inappropriate, such as welding underwater. The thermite reaction is described by the equation below:
Upper F e subscript 2 upper O subscript 3 plus 2 upper A l right arrow upper A L subscript 2 upper O subscript 3 plus 2 upper F e. (see image)
A welder has 1.873 × 102 g Fe2O3 and 94.51 g Al in his welding kit. Which reactant will he run out of first?
How many grams of aluminum oxide are produced in the reaction?
Al is the limiting reactant and would run out quickly and 357 g of aluminum oxide is produced.
What is the limiting reactant?The limiting reactant is the reactant is the reactant that is present in the least amount in the system. This is the reactant that is going to run out most quickly. The limiting reactant would be the one that would determine the amount of product that is formed.
Now the reaction equation is shown in the image attached to the question above.
Number of moles of Fe2O3 = 1.873 × 10^2 g /160 g/mol = 1.17 moles
Number of Al = 94.51 g Al/27 g/mol = 3.5 moles
If 1 mole of Fe2O3 reacts with 2 moles of Al
1.17 moles of Fe2O3 reacts with 1.17 moles * 2 moles/ 1 mole
= 2.34 moles
Hence Al is the limiting reactant and would run out quickly.
Mass of aluminum oxide produced = 3.5 moles * 102 g/mol = 357 g
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Which of the following is a way that human modification of limiting factors causes unbalance in ecosystems.
Answer:
D. all of the above
Explanation:
edg 2021
A way that human modification of limiting factors causes unbalances in ecosystems. are habitat loss, pollution, and climate change. Option D. This is further explained below.
What is an ecosystem.?Generally, An ecosystem is a geographical region in which plants, animals, and other species, as well as weather and topography, coexist to produce a circle.
In conclusion, habitat loss, pollution, and climate change are all human modification of limiting factors causes unbalance in ecosystems.
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CQ
which of the following is a way that human modification of limiting factors causes unbalance in ecosystems? a. habitat loss b. pollution c. climate changes d. all of the above
3. A compound formed of CO2 and water is sour? Why?
Explanation:
it's because when CO₂ reacts with H₂O then it forms H₂CO₃ (carbonic acid), which is a acid that's why a compound formed by CO₂ and H₂O is sour.
Reaction:
CO₂ + H₂O → H₂CO₃
When ionic compounds are added to water, they dissociate or break apart into ions. In the case of table salt, salt added to water dissociates into sodium ions and chloride ions. This would seem to be a chemical change. However, scientists do not consider this to be one, because the solid table salt remains after the water is evaporated. The atoms recombine into their original arrangement once the water is removed. Which word from the selection helps you understand that physical changes can be undone? a added b dissociate c recombine. d removed
Answer:
b dissociate
Explanation:
8.0 g of a monoatomic gas occupies 96.0 L at 380.9 mm Hg and 20.0 °C. What is the identity of the gas?
The monoatomic gas : He
Further explanationIn general, the gas equation can be written
[tex]\large {\boxed {\bold {PV = nRT}}}[/tex]
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
P 380.9 mmHg = 0.5 atm
T 20 C+273 = 293 K
We can find molar mass of gas :
[tex]\tt M(molar~mass(M)=\dfrac{mRT}{PV}\\\\M=\dfrac{8~g\times 0.082\times 293~K}{0.5~atm\times 96~L}\\\\M=4~g/mol[/tex]
monatomic gas means a single element, usually a noble gas. The noble gas element with mass 4 is He
the structure that serves as the outer boundary of the eukaryotic cell is the cell membrane
Answer:
The Plasma Membrane.
Explanation:
The eukoryotic cell is enclosed in a limiting membrane called the Plasma Membrane or Plasmalemma. ❤️
According to Periodic Law, elements arranged in order of increasing atomic number are placed together in groups having
Answer: same valence shell configuration and properties
Explanation:
What is the Mass percent of carbon in glucose, C6H12O6?
Answer:
the answer is 40% but, correct me if I'm wrong
Explanation:
Answer:
40%
Explanation:
Mass of carbon / total mass × 100
72/180× 100 = 40%
If the value of mass doubles but the volume stays the same, the value for density will be
Answer:
if the value of volume doubles but the mass stays the same, the value for density will be 1
When an atom becomes a positive
ion, the radius of the atom
(1) decreases
(2) increases
(3) remains the same
Answer: When an atom becomes a positive ion it pulls it's electrons closer, decreasing it's radius moreover, when it becomes a negative ion, it pulls it's electrons closer and decreases the radius
I hope this helps :)
what is 2 multiplied by 4
Answer:
8
Explanation:
Answer:
the answer is 8 :D
Explanation:
2x4 also known as 2+2+2+2 is equal to 8
Convert 3.30 g of copper (II) hydroxide Cu(OH)2 to molecules.
Answer:
0.18× 10²³ molecules
Explanation:
Given data:
Mass of copper hydroxide = 3.30 g
Number of molecules = ?
Solution:
Number of moles = mass/molar mass
Number of moles = 3.30 g/97.56 g/mol
Number of moles = 0.03 mol
Avogadro number:
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 molecules
0.03 mol × 6.022 × 10²³ molecules / 1mol
0.18× 10²³ molecules
calculates the equivalent mass of calcium chlorate CA (CI03) 2
Answer:
207g
Explanation:
Given compound:
Ca(ClO₃)₂
The equivalent mass can be derived by summing the molar masses of each atom
Molar mass of Ca = 40
Cl = 35.5
O = 16
Now solve;
Molar mass = 40 + 2(35.5 + 3(16)) = 207g
ОА
H+ HH
O H+ H → He
Oc He+
TH
Не
ODH +
Η
>
Ao H+HH OH
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A meterorite has velocity of 1544 m/s and a mass of 45 kg. Find its momentum
Answer:
69,480 kg.m/sExplanation:
The momentum of an object can be found by using the formula
momentum = mass × velocity
From the question we have
momentum = 45 × 1544
We have the final answer as
69,480 kg.m/sHope this helps you
Answer:
69,480 kg. m/s
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4. Compare the diagrams of the two substances shown below.
a. Use your understanding of structure to predict which substance is a gas at room temperature and which is a
at room temperature.
b. Explain your answer using your understanding of the relationship between structure and properties of
substances.
bond-
silicon atom
oxygen atom
Answer:
the anserw is 2
Explanation:
5.69 x 10
5.27 x 1014
How many molecules are found in 3.18 x 10^24 molecules of O2
Answer:
5.28 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{3.18 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 5.282392...[/tex]
We have the final answer as
5.28 molesHope this helps you
Need answers to all these questions asap
Answer:
Li3PO4 + Sn(CH3COO)2 ------> LiSnPo4 + Li2(CH3COO)2
Explanation:
What is the main product of cellular
respiration?
Answer:
The main products are ATP, carbon dioxide, and water.
who is good at chemistry?! HMU asap!!!
Explain the role of photosynthesis in the cycling of matter between the plant and the person?
The process of photosynthesis converts light energy into stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.
What is photosynthesis ?Utilizing a process called photosynthesis, plants and other living things may transform light energy into chemical energy that can then be released through cellular respiration to power their activities. Photosynthesis, from the Greek phs (light) and synthesis (putting together), derives from the fact that some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are created from carbon dioxide and water.
Photoautotrophic organisms, such as the majority of plants, algae, and cyanobacteria, carry out photosynthesis. The majority of the energy required for life on Earth is produced and maintained through photosynthesis, which is also primarily responsible for producing and maintaining the oxygen concentration of the Earth's atmosphere.
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Young trees growing under another tree would cause?
Answer:
competition
Explanation:
it would cause competition. both would fight for water and other stuff to grow and live
Fill in all the grey boxes including the green box. PLEASE HELP
Answer:
2Na + 2H2O ----> 2NaOH + H2
Explanation:
If a 200 kg person stands next to a 100 kg person. Which person would have a larger gravitational attraction?
Answer:
200 kg
Explanation:
the 200 kg person is heavier due to gravity's force the 100 kg person has less force than the other person
Answer:
massive one that is 200kg
Explanation:
Since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. So as the mass of either object increases, the force of gravitational attraction between them also increases.