The reaction is endothermic because the temperature dropped from 28 degrees Celsius to 20 degrees Celsius.
Meaning of endothermic and exothermic reaction:An endothermic reaction is one in which heat is absorbed from the surrounding resulting in decrease in temperature while an exothermic reaction is one in which heat is evolved causing the temperature to rise.
In the particular context of this question, the reaction is endothermic because the temperature dropped from 28 degrees Celsius to 20 degrees Celsius. The heat in the surroundings decreased.
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Write the scientific term "A number used by Bohr in the explanation of the spectrum of hydrogen atom and designated by the symbol (n) " ?
Answer:
Quantum number
Explanation:
what is actually chemistry
Answer:
Chemistry is the branch of science that deals with the properties, composition, and structure of elements and compounds, how they can change, and the energy that is released or absorbed when they change.
Answer:
Well my teacher said a more complex way he said chemistry is the science that deals with the properties, composition, and structure of substances.
Explanation:
Give atleast 5 differences in cell structures of plant and animal cells
Find the mass in kilograms of the liquid air that is required to produce 600L of oxygen. In normal condition, 1L of liquid air has 1.3g
Explanation:
1L is 1.3 g so 600L is 780 g
1kg= 1000g so
780 g = 0.78kg
I GUESS
Mass in kilograms of liquid air required = 0.78 kg
Given that
1 Litre of liquid air contains 1.3 grams of oxygen ( air )
Determine the amount of liquid air in Kg
volume of air given = 600 L
mass of liquid air required = x
1 litre = 1.3 grams
600 L = x
∴ x ( mass of liquid air ) = 1.3 * 600
= 780 g = 0.78 kg
Hence we can conclude that Mass in kilograms of liquid air required = 0.78 kg
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An electron is present at an energy level with an energy of 16.32 x 10−19 J. During a transition to another level, 5.4 x 10−19 J of energy was absorbed. Which of the following is true about the present state of the electron?
Answer Choices:
A. The electron moved down to an energy level and has an energy of 10.92 x 10−19 J.
B. The electron moved down to an energy level and has an energy of 21.72 x 10−19 J.
C. The electron moved up to an energy level and has an energy of 10.92 x 10−19 J.
D. The electron moved up to an energy level and has an energy of 21.72 x 10−19 J.
Answer:
D. The electron moved up to an energy level and has an energy of 21.72 x 10−19 J.
The statement which is true about electrons is that the electron moved up to an energy level and has an energy of 10.92 x 10[tex]^-[/tex]¹⁹ J which is found out as 16.32 x 10[tex]^-[/tex]¹⁹ -5.4 x 10[tex]^-[/tex]¹⁹=10.92 x 10[tex]^-[/tex]¹⁹ J.
What is an energy level?Electrons present in an atom revolve in different orbits which are stationary states and are also called as energy levels. The energy levels are numbered as integers which are also called as principal quantum numbers.
Energy of the stationary state is given as E= -R
1/n² where R
is the Rydberg's constant. When an electron is excited, and it moves from lower to higher energy levels there is absorption of energy, while when it moves from higher energy level to lower energy level it radiates or gives out energy in the form of radiation.
They can also be defined as the distances between electron and nucleus of an atom . Electrons present in K energy level have least energy .Energy level diagrams are studied to understand nature of bonding , placement of electrons in orbits and and elemental behavior under certain conditions.
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Describe how this instrument works.
(legit this is 100pts so uhh help)
Operation
Answer:
This is a reflector telescope and in which it captures different wavelengths of light and it hits one mirror, bounces back and hits another and then is shown through the eyepiece. It captures all of the visible spectrum and some areas above and below it. These telescopes are better for seeing big picture and not the fine details in planets surfaces.
Hope this helps!
Explanation:
Answer:
This is a reflector telescope and in which it captures different wavelengths of light and it hits one mirror, bounces back and hits another and then is shown through the eyepiece. It captures all of the visible spectrum and some areas above and below it. These telescopes are better for seeing big picture and not the fine details in planets surfaces.
Hope this helps!
Explanation:
which describes an attribute of nonrenewable resources
Answer:
atributes of nonrenewable recources are things you cant re use after 1 use like gas
Explanation:
Answer: the answer is b. Are unlimited
Explanation:
23.
What would happen to the substance in the jar if energy was added?
Answer:
it would explode
Explanation:
dont put that as an answer i need point for finals
What happens in cellular respiration?
The answer would be B.
When glucose reacts with oxygen, it forms an ATP that is used by the given cell. Co2 and h2O are the byproducts.
which statement describes how the binary ionic compound cacl2 is named?
what are the three molecules that are attached to the plasma membrane, and what are their roles/ functions?
Answer:
Ans:
*Carbohydrates
*Proteins
*Cholesterol
Explanation:
The plasma membrane is a structure that has several distinct roles in the cell
The plasma membrane is mainly composed of the phospholipid Bilayer, which is a layer of two sheets located in the internal and external parts. The Phospholipids are said to be Amphipathic because they have both properties of Hydrophobic and hydrophilic
*The Carbohydrate Molecules attach to the Plasma Membrane such as to the lipids and Proteins:
when They attach to the Proteins, they are known as glycoproteins, and they help in cell recognition, when they attach to the lipids, they are known as Glycolipids
*Protein Molecules play an important role in transport system such as Carrier Proteins
*Cholesterol Molecules help in balancing the Fluidity of the plasma membrane
hope this was of use
When potential energy is converted into kinetic energy, some of that energy is always in the form of:
А.
light energy
B.
chemical energy
с
nuclear energy
D
heat energy
A 24.81-g sample of a gaseous compound containing only carbon, oxygen, and chlorine is determined to contain 3.01 g C, 4.00 g O, and 17.81
g Cl. What is this compound's percent composition?
Explanation:
getting the empirical formula
For carbon
3.01/12 = 0.2508
For oxygen
4/16 = 0.25
For Cl
17.81/35.5= 0.501
0.2508 ÷ 0.25 = 1.0032
0.25 ÷ 0.25 = 1
0.501 ÷ 0.25 = 2.004
Empirical formula of the compound = CCl20
Molar mass = (1×12) + (2×35.5) + (1×16)
= 12 + 71 + 16
= 99g/mol
percentage composition= 24.81/99 × 100
= 25.06%
A 24.81-g sample of a gaseous compound containing only carbon, oxygen, and chlorine is determined to contain 3.01 g C, 4.00 g O, and 17.81 g Cl. the compound's percent composition is 25.06%.
What are the application of carbon ?The impure form of carbon is Amorphous which is used for the manufacture of car batteries and dry cells, ink and paints; So the majority element of carbon is present in charcoal, so these are used as fuel.
Graphite is derivative form of carbon used as a lubricant in heavy industrial machinery, making pencil leads, these carbon are used in the production of steel.
The empirical formula, For carbon 3.01/12 = 0.2508
For oxygen 4/16 = 0.25, For Cl 17.81/35.5= 0.501, 0.2508 ÷ 0.25 = 1.0032
0.25 ÷ 0.25 = 1
0.501 ÷ 0.25 = 2.004
Empirical formula of the compound = CCl20
Then the Molar mass = (1×12) + (2×35.5) + (1×16)
= 12 + 71 + 16
= 99g/mol
percentage composition= 24.81/99 × 100
= 25.06%
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look at attachment please help with it, will mark brainliest <3 BUT ONLY IF CORRECT
Passing an electric current through a sample of water (H2O) can cause the water to decompose into hydrogen gas (H2) and oxygen gas (O2) according to the following equation. 2H2O Right arrow. 2H2 O2 The molar mass of H2O is 18. 01 g/mol. The molar mass of O2 is 32. 00 g/mol. What mass of H2O, in grams, must react to produce 50. 00 g of O2? 14. 07 23. 05 28. 14 56. 28.
The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.
The reaction for the decomposition of water has been:
[tex]\rm 2\;H_2O\;\rightarrow\;H_2\;+\;O_2[/tex]
From the balanced equation, 2 moles of water decomposes to form 1 moles of hydrogen and 1 mole of oxygen.
The mass of oxygen produced has been 50 g. The moles of oxygen has been given by:
[tex]\rm Moles=\dfrac{mass}{molar\;mass}[/tex]
The moles of oxygen has been:
[tex]\rm Moles_O_2=\dfrac{50}{32}\;mol\\Moles_O_2=1.5625\;mol[/tex]
The moles of oxygen produced has been 1.5625 mol.
The moles of hydrogen decomposed has been given from the balanced chemical equation as:
[tex]\rm 1 \;mole\;O_2=2\;mole\;H_2O\\1.5625\;mol\;O_2=1.5625\;\times\;2\;mol\;H_2O\\1.5625\;mol\;O_2=3.125\;mol\;H_2O[/tex]
The moles of hydrogen decomposes has been 3.125 mol.
The mass of hydrogen decomposed has been given by:
[tex]\rm Mass=moles\;times\;molar\;mass\\Mass_{H_2O}=3.125\;\times\;18.01\;g\\Mass_{H_2O}=56.28\;g[/tex]
The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.
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What state of matter has a defined volume but undefined shape?
Question 6 options:
gases
liquids
solids and liquids
liquids and gases
Answer:
Liquids
Explanation:
They have a certain volume but they take the shape of their container
who is credited with developing the periodic table
Answer:
Dimitri mendleev and Albert something. I forgot his last name. I think ghorso. Albert ghorso.
“Burning of fossil fuels causes pollution.” Suggest alternative methods by
which we can overcome this global issue in less than 250 words.
An alternative method by which we can overcome this global issue is by harnessing Solar energy.
Discussion:
Fossil fuels cause environmental pollution. This is because they are organic compounds and on combustion, they release air pollutants such as, Carbon monoxide.
As a panacea, the use of solar panels for harnessing Solar energy in a bid to replace energy from fossil fuels will prove to be am effective method by which we can overcome the global issue of pollution caused by burning of fossil fuels.
Solar energy is a clean source of energy as there's no release of harmful air pollutants.
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Alternative method by which we can overcome this global issue is by
harnessing energy with less form of pollution. These include:
Solar energyHydropowerNuclear energyFossil fuel burning releases greenhouse gases such as Carbon dioxide,
nitrous oxide etc which causes pollution to the atmosphere.
It is best to adopt alternative methods mentioned above to ensure pollution
is reduced to the barest minimum. This helps to prevent ozone depletion and
global warming. It also reduces risks of respiratory diseases due to the
inhalation of the gases.
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what happens to glucose in the body?
After your body has used all the energy it needs, leftover glucose is stored in the liver and muscles. We can store enough fuel for about a day, if you haven't eaten in a while, your blood glucose level drops. :)
Hope this helps!
15) The chemical formula of a compound indicates the
A) relative proportions of the elements in the compound
B) identity of the elements in the compound only
C) type and arrangement of the bonds in the compound
D) three-dimensional structure of the compound
Which statement best describes what happens to the stability of hydrogen and oxygen atoms when they form bonds in a water molecule?
Answer:
It's c
Explanation:
Because I've checked
isotopes of an element contain different numbers of
carbondiooxide does not support in burning but mg burs in it why.?
To keep burning, fires require oxygen. Carbon dioxide is used in certain fire extinguishers to put out flames. Explanation: Because magnesium is higher on the reactivity scale than carbon, it is more reactive and eliminates oxygen from carbon dioxide (to give carbon and magnesium oxide).
how many grams of baf2 are dissolved in 75.0 ml of a saturated solution of baf2? ksp = 1.00 x 10-6
Using the solubility product of the saturated solution, the mass of BaF2 dissolved is 0.083 g.
The equation of the reaction is obtained from;
BaF2(s) ⇄ Ba^+(aq) + F^-(aq)
The concentration of the substance can be obtained from the Ksp as follows;
Ksp = [Ba^2+] [2F^-]^2
Ksp = 4x^3
x = ∛Ksp/4
x = ∛ 1.00 x 10-6/4
x = 6.3 x 10^-3 M
Given that;
mass/molar mass = concentration x volume
molar mass = 175 g/mol
concentration = 6.3 x 10^-3 M
volume = 75.0 ml or 0.075 L
Mass = ?
Mass = concentration x volume x molar mass
Mass = 6.3 x 10^-3 M x 0.075 L x 175 g/mol
Mass = 0.083 g
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Fill in the blanks:
87 pg = [? ]x10^[?]g
87 picograms are equivalent to [tex]8.7\times 10^{-11}[/tex] grams.
This is a unit problem, in which a derived unit must translated into a fundamental unit. A picogram is a equivalent to a trillionth of a gram, which is the fundamental SI mass unit. Mathematically speaking, we have the following equivalence:
[tex]1\,pg = 1\times 10^{-12}\,g[/tex]
Now we proceed to find the equivalent value for this case:
[tex]87\,pg[/tex]
[tex]87\times 10^{-12}\,g[/tex]
[tex]8.7\times 10^{-11}\,g[/tex]
87 picograms are equivalent to [tex]8.7\times 10^{-11}[/tex] grams.
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How does thermal energy flow?
Answer:
Thermal energy typically flows from a warmer material to a cooler material.
Explanation:
I know the answer is A/1 but I’m not sure how to explain it, I would like some help on the explanation part
3. The accompanying diagram represents a cell in water. Formulas of molecules that can move freely across the cell membrane are shown. Some molecules are located inside the cell and others are in the water outside the cell.
(Picture) diagram
Based on the distribution of these molecules, what would most likely happen after a period of time?
A. The concentration of O₂ will increase inside the cell.
B. The concentration of CO₂ will remain the same inside the cell.
C. The concentration of O₂ will remain the same outside the cell.
D. The concentration of CO₂ will decrease outside the cell.
Answer:
number one is the correct option
(01.07 HC)
A student collected the data shown in the table below during an experiment.
Liquid Characteristics
Liquid Characteristics
Boiling Point Freezing Point Color Expansion per Degree Change in Temperature
Mercury 357 °C −39 °C shiny silver gray relatively lower
Alcohol 78 °C −115 °C colorless relatively higher
Based on the data, which of the following conclusions can be made about the use of mercury and alcohol thermometers?
A mercury thermometer can measure the freezing point of a liquid that freezes at −80 °C.
An alcohol thermometer can measure the boiling point of a liquid that boils at 80 °C.
A mercury thermometer is better to measure very small changes in temperature.
An alcohol thermometer is better to measure the boiling points of colorless liquids.
Answer: a mercury thermometer is better to measure very small changes in temperature
Explanation:
i took the test and got it right
Answer:
the answer is C, a mercury thermometer is better to measure very small changes in temperature.
Explanation:
i just took the test and it was correct :)
PLEASE HELP I DON´T KNOW WHAT THE DIFFERENCE BETTWEEN THE TWO IS!
What is the difference between a product and a reactant.
Answer:
A reactant is a substance that is present at the start of a chemical reaction. A product is a substance that is present at the end of a chemical reaction.
Explanation:
What is the pH of a substance that has [H+] = 0.0081?
8.1
-1.09
-8.1
1.09