Answer:
3.
[tex]{ \tt{Na {}^{ + } }} \: is \: an \: ion[/tex]
10. A laboratory experiment requires that
exactly 3 mL of chemical be dispensed into a
test tube. Which piece of equipment would be
MOST appropriate for measuring and
dispensing the chemical?
A another test tube
B a pipette
C a beaker
D a scale balance
Answer:
B) a pipette
Explanation:
Also known as a graduated pipette, they vary in volume, with most measuring between 0 and 25.0 mL. A small pipette can be used for precise measurement of fluids.
please help in all 3 questionnn
Answer:
Explanation:
a) photosynthesis
b) Substances used: water, sun, gas and nutrients. Products: glucose and flowers
c) there will be no sunlight or no open environment
What does the emission spectrum of a molecule show?
A. The energy the molecule absorbs as it undergoes a reaction to break down into its elements
B. The wavelengths of light a molecule gives off when an electron moves to lower energy levels
C. The wavelengths of light a molecule takes in when an electron moves to a higher energy level
D. The energy the elements give off as they undergo a reaction to form a molecule
Answer:
B. The wavelengths of light a molecule gives off when an electron moves to lower energy levels
Explain and describe how the photoelectric effect occurs on an atomic level in terms of protons, neutrons, and electrons
Answer:
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons.
Based on the wave model of light, physicists predicted that increasing light amplitude would increase the kinetic energy of emitted photoelectrons, while increasing the frequency would increase measured current.
5 grams of iron react with 5 grams of oxygen to produce iron 3 oxide. If I produce 5 grams of product what is my percent yield?
Answer:
5 grams of iron react with 5 grams of oxygen to produce iron 3 oxide.
The actual yield of the reaction is--- 5 grams.
What is the percent yield?
Explanation:
The balanced chemical equation of the reaction is:
[tex]4Fe(s)+3O_{2} (g)->2Fe_{2} O_3(s)[/tex]
1)Identify the limiting reagent.
2)Using the limiting reagent calculate the amount of theoretical yield formed.
Identification of limiting reagent:
4 mol of Fe reacts with 3mol. of O2
that is:
4mol(55.84g/mol) of Fe reacts with ---- 3mol (32.0g/mol)
=223.36g of Fe reacts with ---- 96g. of O2
then,
5g of Fe requires how many grams of O2?
[tex]=>5g. of Fe * \frac{96g O2}{223.36g Fe} \\=2.14g. of O_{2} .\\[/tex]
But provided 5g of O2.
So, O2 is present more than required.
Hence, O2 is the excess reagent and the limiting reagent is Fe.
The amount of product formed depends only on the amount of Fe only.
Theoretical yield:
From the balanced chemical equation:
4mol. of Fe forms ----- 2mol. of Fe2O3.
that is
223.36g of Fe forms --- 2(159.68g)of Fe2O3.
=>223.36g of Fe forms --- 319.36g of Fe2O3.
then,
5g of Fe forms ----? grams of Fe2O3
[tex]=>5g of Fe * \frac{319.36g Fe2O3}{223.36g of Fe} \\=7.14g. of Fe2O3\\[/tex]
[tex]%Error =\frac{actual yield}{theoretical yield} * 100\\\\ %error=\frac{5g}{7.14g} * 100\\ %error =70.0[/tex]% error=actual yield/ theoretical yield x 100
%error=5g./7.14g x100
=>%error=70.0
Hence, the answer is 70.0%.
is radiation beneficial or harmful to society explain why
Answer:
Radiation isn't beneficial to society .Radiation damages the cells that make up the human body. Low levels of radiation are not dangerous, but medium levels can lead to sickness, headaches, vomiting and a fever. High levels can kill you by causing damage to your internal organs. It's difficult to treat high radiation exposure.
Explanation:
Exposure to very high levels of radiation, such as being close to an atomic blast, can cause acute health effects such as skin burns and acute radiation syndrome (“radiation sickness"). It can also result in long-term health effects such as cancer and cardiovascular disease.
Radiation is both harmful and beneficial, but when we analyse it is found that harms overweight benefits. Radiation can be used as a form of energy (in nuclear plants), but an accident or malfunction in it can lead to death and injury of humans. Also, it is really difficult to dispose the used devices.
Chemical bonding may involve any of the following except the
1. change in mass in a chemical reaction
2. unequal sharing of a pair of electrons between two nonmetals
3. electrostatic attraction between two ions
4. transfer of an electron from one atom to another
Answer:
Number 1 is wrong it doesn't change the mass
Chemical bonding may involve any of the following except the " change in mass in a chemical reaction".
What is chemical reaction?A chemical reaction is referred to as a process which it involves the chemical change of one set of chemical compounds into yet another set of chemical substances.
What is chemical bonding?A molecule and compound's atoms, ions, and groups of atoms are held together by an attractive force, referred as chemical bond.
Chemical bonding may involve any of the following except the " change in mass in a chemical reaction".
Therefore, the correct answer will be option 1.
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Two students were discussing the Mono Lake ecosystem. The first student said, "For a 20-kilogram (kg) coyote to survive, it takes around 200 kg of Wilson's phalaropes, 400 kg of brine shrimp, and 800 kg of algae!" The second student said, "No, I think it takes even more than that." 1. Which student is correct? What is your reasoning?
Answer:
The second student is right.
Explanation:
The coyote feed on not only phalaropes but many other organisms present in the environment for its survival. There are many other organisms present in the ecosystem such as mice, squirrel, cactus fruit etc. The coyote feeds on phalaropes, the phalaropes feeds on brine shrimp and the brine shrimp feeds on algae for its survival so in this way the ecosystem moves in the forward direction. The coyote feeds on phalaropes so the energy that is present in phalaropes transferred into coyote which only 10 % while the remaining is released in the atmosphere in the form of heat energy.
I need help finding out what this is please help
Answer:
search the Lewis dot structure you will know the answer.
Tea contains which acid?
A
Tannic acid
B
Tartaric acid
C
Carbonic acid
D
Citric acid
When copper is heated in air, the solid product that is formed has a greater mass than the original copper. When calcium carbonate is heated in air, the solid product that is formed has less mass than the original
calcium carbonate. Why is the mass of the solid product greater in one reaction but less in the other reaction?
Answer:
When heated, oxygen reacts with copper to form copper oxide. If this reaction occurs in a sealed container, will the mass of the container and everything in it increase, decrease, or stay the same and why? The mass will increase because a new kind of molecule is formed.
Explanation:
As above, carbonates decompose upon heating to give the metal oxide and carbon dioxide. The mass is lost as carbon dioxide.
To solve this we must be knowing each and every concept related to mass. Therefore, Carbon dioxide is released as the mass is depleted when carbonates are heated.
What is mass?Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes.
When copper was heated in the air, the resulting solid product has a larger mass than the initial copper. When calcium carbonate was heated in air, the resulting solid product has much less mass than the initial calcium carbonate. When carbonates are heated, they breakdown into metal oxides and carbon dioxide. Carbon dioxide is released as the mass is depleted.
Therefore, Carbon dioxide is released as the mass is depleted.
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You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following statements is true? Group of answer choices The water is the solute portion of the drink. The instant coffee and sugar dissolve because they have no charged regions to repel the partial positive and partial negative regions of the water molecules. The instant coffee and sugar are solvents. You've just prepared an aqueous solution.
Answer: The statement, you've just prepared an aqueous solution is true.
Explanation:
When one or more number of substances are dissolved in a solvent like water then solution formed is called an aqueous solution.
For example, when a hot drink is made by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water is an aqueous solution.
Here, both coffee and sugar are solute whereas hot water is the solvent.
Thus, we can conclude that the statement, you've just prepared an aqueous solution is true.
Some factories that burn coal produce smoke with harmful chemicals,
such as sulfur. Scrubbers are devices that are attached to the
smokestacks to reduce the amount of sulfur put into the atmosphere. To
evaluate the effectiveness of these devices, what data would need to be
collected?
The amount of sulfur emitted by a smokestack before and after the scrubber is attached.
Hope it helps you I'm from ph❤️
WHAT IS THE DIFFERENCE BETWEEN HALF CELL REACTION AND FULL CELL REACTION
Answer:
It is the amount of energy needed to move an electric charge across a cell
Explanation:
Thank you so much !!!!!!!!!!!!!!!which synthetic fiber feels like wool and used as a substitute for wool
Answer:
Acrylic
Acrylic is the synthetic fibre feels like wool and used as a substitute for wool.
Physical properties can be divided into two categories. _______ depend on the amount of matter present, while _______ don't.
Nitrogen in plants and soil is changed into nitrogen compounds by _____.
nitrogen fixation
respiration
denitrification
photosynthesis
Answer:
A
Explanation:
because It's the process by which atmospheric nitrogen is converted either by a natural or an industrial means to form of nitrogen such as ammonia.
Is the number of electrons in different shells of an atom fixed or unlimited ? Explain by giving an example.
Answer:
the number of electrons in a particular shell is given by the formula 2n^2 . However an electron when gets very exicited loose energy in the forms of radiation and comes in high energy level shell.
The chart shows the bids provided by four contractors to complete a job. Which contractor is the most cost-effective? Joshua Carmen Dante Alicia
Chart for question attached
Answer:
Joshua
Explanation:
By cost-effective here, we mean the contractor that does the job best at the shortest time and lowest money cost. To get this, we calculate total cost for each contractor and then consider time for completion of the job:
Joshua charges $25 per hour for 5 hrs
Carmen charges $20 per hour for 7 hrs
Dante charges $30 per hour for 6 hrs
Alicia charges $20 per hour for 8 hrs
Joshua's cost= $25×5=$125 in 5 hours
Carmen's cost = $20×7= $140 in 7 hours
Dante's cost= $30×6=$180 in 6 hours
Alicia's cost= $20×8= $160 in 8 hours
From the above we can see that Joshua is the most cost-effective contractor given that he completes the job in less time and with less money.
What is the balanced chemical reaction when Aluminium reacts with NaOH to produce NaAlO2 and H2 gas?
Answer:
2NaOH + 2Al +2H2O = 2NaAlO2 +3H
Explanation:
Aluminum is an amphoteric element it reacts with both bases and acids to form a salt and hydrogen gas.The reaction is highly exothermic.
a what is acrylic
b state the important use of acrylic fiber
What type of force are you exerting when you lie on a bed?
A. Electric force
B. Magnetic force
C. Compression
D. Tension
Answer:
C. Compression
Explanation:
I'm pretty sure it's compression
Which of the following is not a reason why actual yield is less than theoretical yield?
A. presence of impure reactants
B. conservation of mass
C. competing side reactions
D. loss of product during purification
The option that isn't a reason why the actual yield is less than theoretical yield is B. conservation of mass.
It should be noted that the formula for the percent yield is given as:
= Actual yield / Theoretical Yield × 100
The actual yield is experimentally determined, and it's the quantity of a product that is gotten from a chemical reaction.The theoretical yield is the amount of product that can be obtained from a reaction when the reactants are changed to products.Actual yield can be less than theoretical yield due to the presence of impure reactants ,competing side reactions, and loss of product during purification.
In conclusion, the correct option is B.
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can
someone please help
Answer: protein bar,it gives alot of energy and wont upset your stomach!!
Chất được chia làm bao nhiêu loại? Lấy ví dụ cho từng loại.
Se puede inferir que el órgano de los sentidos que contiene un mayor número de terminaciones nerviosas debido a su extensión es *
Answer:
La piel.
Explanation:
La piel es el órgano que forma el límite del cuerpo con el mundo exterior. La piel sirve para varios propósitos. Protege al cuerpo de influencias externas como el calor, el frío, la radiación o las bacterias y ayuda a mantener un ambiente interno estable. La piel está fuertemente atada a los huesos y tejidos. Por lo general, la piel alberga más de 100 especies bacterianas diferentes y algunas investigaciones sugieren que la mayoría de estas bacterias son beneficiosas y aumentan la probabilidad de que se evite la infestación de parásitos.
A flexible container has 5.00 L of nitrogen gas at 298 K. If the temperature is
increased to 333 K, what will be the new volume of that sample of nitrogen?
1) 0.179 L
2) 0.223 L
3) 4.47 L
4) 5.59
Answer: 5.59 L
Explanation: I'm pretty sure it's this. I just took this test and got it right. Hope this helps you out! :))
Answer:
5.59 L
Points earned on this question: 4
Explanation:
took the test
what is the oxidation state of p in po4 3
Answer:+5
Explanation: A P3X
A gas has a pressure of 2.36 kPa at 62 °C. What is the pressure at standard
temperature?
Answer:
P2 = 1.94 kPa
Explanation:
Given the following data;
Initial pressure = 2.36 kPa
Initial temperature = 62°C
Standard temperature = 0°C
Conversion:
Kelvin = 273 + C
Kelvin = 273 + 62 = 335 K
Kelvin = 273 + 0 = 273 K
To find the final pressure, we would use Gay Lussac's law;
Gay Lussac states that when the volume of an ideal gas is kept constant, the pressure of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Gay Lussac's law is given by;
[tex] PT = K[/tex]
[tex] \frac{P1}{T1} = \frac{P2}{T2}[/tex]
Making P2 as the subject formula, we have;
[tex] P_{2}= \frac{P1}{T1} * T_{2}[/tex]
[tex] P_{2}= \frac{2.36}{335} * 273 [/tex]
[tex] P_{2}= 0.0071 * 273 [/tex]
P2 = 1.94 kPa
what mass of small stones would be needed to make the strongest concrete? give a reason for your awnser.
Answer:
For a good consert mix aggregate needed to the clean hard strong partical free of absorb chemicals or coating clay and other fine materials
