A piece of unknown metal weighs 500 g. When the piece of metal absorbs 6.64 kJ of heat, its temperature increases from 25°C to 78°C. What's the specific heat capacity
of this metal?
A. 13 J/gºC
B. 0.25 J/gºC
C. 25 J/gºC
D.2.5 J/g °C
6.64×1000÷(78-25)×500=0.25 g/k
Answer:
6.64×1000÷(78-25)×500=0.25 g/k
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Put the steps of the scientific method into the correct order.
Devise an experiment to prove or disprove.
State conclusions.
Conduct a literature search.
Define the problem.
Propose a hypothesis.
Answer:
1. Define the problem
2. Conduct a literature search
3. Propose a hypothesis
4. Devise an experiment to prove or disprove
5. State conclusions
Explanation: In order to begin an experiment, you must first define a problem or question that you will be answering. Then you must research the problem in order to form a hypothesis, or an educated guess. Then you should devise and execute an experiment to answer your question. The conclusions that you draw will either prove or disprove your hypothesis. Hope this helps!
calculate the number of moles equivalent to 12.7 gram of iodine molecule
[tex] \LARGE{ \boxed{ \purple{ \rm{Answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{I_2}[/tex]
How to find?
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
[tex] \boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}[/tex]
Solution:
❍ Molecular weight of [tex]\sf{I_2}[/tex]
= 2 × 126.90
= 253.80
= 254 (approx.)
❍ Given weight: 12.7
Then, no. of moles,
⇛ No. of moles = 12.7 / 254
⇛ No. of moles = 0.05 moles
⚘ No. of moles of Iodine molecule in the given weight = 0.05 moles
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Answer:
The answer is 0.05 molExplanation:
To find the number of moles (n) we use the formula
[tex]n = \frac{m}{M} [/tex]
Where
n is the number of moles
m is the mass of the substance
M is the molar mass
To find the number of moles we must first find the molar mass
Since iodine is a diatomic molecule
M( I ) = 127 × 2 = 254 g/mol
Mass of iodine = 12.7 g
So the number of moles in 12.7 g of iodine is
[tex]n = \frac{12.7 \: g}{254 \: g/mol} [/tex]
We have the final answer as
n = 0.05 molHope this helps you
How can you guess the name of the element using the chemical formula ?
The number of protons define what element we're dealing with.
Answer: The number of protons define what element we're dealing with.
The subscripts in a chemical formula are the number of
of a particular atom in one mole of the molecule.
A. reactants
B. atoms
C. moles
D. molecules
Answer:
d.molecules.its the answer.
Answer: B. molecules
Explanation:
it is the answer
Which of the following reactions are possible if sodium is more reactive than aluminum, 3 iron, and lead?
Reaction I: Sodium + Aluminum chloride →Sodium chloride + Aluminum Reaction II: Sodium chloride + Iron → Iron chloride + Sodium
Reaction III: Sodium + Lead chloride → Sodium chloride + lead
Answer:
Reaction I: Sodium + Aluminum chloride →Sodium chloride + Aluminum
Explanation:
Sodium being more reactive means that it will take the place of aluminium in whats called a displacement reaction and form.
Sodium chloride + Aluminum
Please help with questions 11-13! I’ll give brainliest
Who invented the Periodic table? And why Periodic tables are useful?
Answer:
It also helps them understand how life works. It even helps them predict how new materials will behave. In 1869, Dmitri Mendeleev, a Russian chemist, proposed the periodic law and his first periodic table. He published this periodic table two years later in a textbook, The Principles of Chemistry.
Explanation:
Answer:
Dmitri Mendeleev, To summarize, the periodic table is important because it is organized to provide a great deal of information about elements and how they relate to one another in one easy-to-use reference. The table can be used to predict the properties of elements, even those that have not yet been discovered
Explanation:I have already done this
Why do scientific ideas sometimes change???
Plss help I will give branliest!! :)
Answer:
A scientific idea is an explanation of how something works, or the truth about some aspect of the world, that was figured out using the scientific process. ... Scientific ideas change over time as our evidence improves. The more experiments we do and the more data we collect, the better our scientific ideas become.
hope that helps you
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Changes can be brought about by new scientific discoveries, but they can also be influenced by social, political, or religious beliefs.
What is scientific ideas?A scientific idea is a scientific explanation of how something works or the truth about some aspect of the world that was discovered through the scientific process.
Science is the process by which we make sense of the world by collecting data and conducting experiments. As our evidence improves, scientific ideas evolve.
A scientific theory is a well-supported explanation of some aspect of the natural world based on a simplicity of facts which have been cross checked repeatedly via observation as well as experiment.
Such fact-supported theories are not guesses, but rather reliable accounts of reality.
As our evidence improves, scientific ideas evolve. The more experiments we conduct and data we collect, the more refined our scientific theories become.
Thus, due to this the scientific ideas sometimes change.
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are mountains physical or chemical property
Is water a physical or chemical property
is a box a physical or chemical property
is a lion a physical or chemical property
Answer:
Answer: mountains not sure
Water is chemical
Box is physical
Lion is physical
Hope this helped!!
Explanation:
What are some examples of how science can help us in our everyday lives???
PLSSS HELP! I will give brainliest!! I'll give 20 points for it!!
Answer:
Science can help us in many ways in our daily life, It helps us develop skills, like the ability to play an instrument or the ability or learn and communicate, science has made our life easier such as the discovery of technology. Recently, because of the pandemic, technology has help us communicate with each other.
Explanation:
It helps us live a longer and healthier life by monitoring our health, providing medicine to cure our diseases, relieving aches and pains, and assisting us in providing water for our basic needs.
What is science?Science is any system of knowledge concerned with the physical world and its phenomena, requiring unbiased observations and systematic experimentation.
A science, in general, is the pursuit of knowledge concerning general truths or the operations of fundamental laws.
It helps us live a longer and healthier life by monitoring our health, providing medicine to cure our diseases, relieving aches and pains.
Also assisting us in providing water for basic needs such as food, providing energy, and making life more enjoyable through sports, music, and entertainment, among other things.
Cooking, eating, breathing, driving, and playing all involve science. Everything we wear, the brush and paste we use, the shampoo, talcum powder, and oil we apply is a result of scientific advancement.
Thus, this way the science is used in everyday life.
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i need help asap. any help is appreciated.
the diagram shows an electrochemical cell with copper (left) and zinc (right) strips.
**Label all parts (1-9), including the solutions in each beaker and the connecting tube
**Label which cell is the cathode and which cell is the anode include the charge on each strip
**Show, or describe in detail, the flow of electrons
**Describe what type of electrochemical cell is pictured. Explain how the cell works Include the oxidation the oxidation half-reacions in your explanation
Answer:
Explanation:
1- Cathode 2- copper electrolyte solution usually (CuSO4) 3- Cu half cell 4- bulb (when lighted, shows the current is flowing) 5- Zn half cell 6- Zn electrolyte solution 7- connecting wires 8- anode (Zn) 9-salt bridge
2- the copper-(Cu) electrode is the cathode and the zinc-(Zn) electrode will be the anode. This is because the cathode is negatively charged (while Cu is positively charged, so it attracts) and the anode is positively charged (while Zn will be negative)
3- the electrons flow from the anode, where oxidization takes place, to the cathode, where reduction reactions take place.
That's the best i can do. Hope it helps.
Answer:
Explanation:
• Label all parts (1–9), including the solutions in each beaker and the connecting tube.
1. Copper strip
2. Cu2+(aq) (copper electrolyte solution or copper nitrate)
3. Cathode compartment
4. Light bulb
5. Anode compartment
6. Zn2+ (aq) (zinc electrolyte solution or zinc nitrate)
7. The connecting wires or the external circuit
8. Zinc strip
9. Salt bridge
• Label which cell is the cathode and which cell is the anode. Include the charge on each strip.
The copper strip is the cathode and the zinc strip is the anode. The anode is positively charged and the cathode is negatively charged. This is because the cathode attracts a positive charge and the anode attracts a negative charge.
• Show, or describe in detail, the flow of electrons.
The atoms from the zinc strip are oxidized into zinc ions, (the anode is where oxidation occurs). The electrons in the anode then travel through the wire to the copper strip. The electrons then merge with the copper ions in the solution creating copper metal (the cathode is where reduction occurs).
• Describe what type of electrochemical cell is pictured. Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.
This is a voltaic or galvanic cell. It works by using spontaneous oxidation-reduction reaction to generate electricity.
Zn(s) --- Zn2 + (aq) + 2e-
Cu2 + (aq) + 2e- --- Cu(s)
Why do scientists need to be able to use math?
How many sulfur atoms are generated when 9.42 moles of H2S react according to the following equation: 2H2S+SO2→3S+2H2O
A) 8.51 × 10^24
B) 3.78 × 10^24
C) 8.51 × 10^23
D) 9.42 × 10^23
Answer:
A) 8.51 × 10²⁴
Explanation:
1. Gather all the information
2H₂S + SO₂ ⟶ 3S + 2H₂O
n/mol: 9.42
2. Calculate the moles of S atoms
The molar ratio is 3 mol S:2 mol H₂S
[tex]\text{Moles of S} = \text{9.42 mol H$_{2}$S} \times \dfrac{\text{3 mol S }}{\text{2 mol H$_{2}$S }} = \text{14.13 mol S}[/tex]
3. Calculate the atoms of S
[tex]\text{Atoms of S } = \text{14.13 mol S} \times \dfrac{6.022 \times 10^{23}\text{ S atoms}}{\text{1 mol S}} = \mathbf{8.51 \times 10^{24}}\textbf{ S atoms}[/tex]
The sulfur atoms that should be generated is [tex]A) 8.51 \times 10^24[/tex].
Given that,
9.42 moles of H2S reacted to the given equation.Also, 1 mole for the substance contains [tex]6.022 \times 10^23[/tex] no of atoms & molecules. The calculation is as follows:[tex]= \frac{3\times 6.022\times 10^23\times 0.42}{2}\\\\= 85.0909 \times 10^23\\\\= 8.509 \times 10^24\\\\= 8.51 \times 10^24[/tex]
Therefore we can conclude that the sulfur atoms that should be generated is [tex]A) 8.51 \times 10^24[/tex].
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calculate the number of moles equivalent to 5.0 gram of calcium oxide
please help
Answer:
The answer is 0.089 molExplanation:
The number of moles of a substance can be found by
[tex]n = \frac{m}{M} [/tex]
where
n is the number of moles
M is the molar mass
m is the mass of the substance
To find the number of moles we must first find the molar mass
Chemical formula for calcium oxide is
CaOSo the molar mass of CaO is
M( CaO) = 40 + 16 = 56 g/mol
Mass of CaO = 5.0g
Substitute the given values into the formula
The number of moles in 5.0g of calcium oxide is
[tex]n = \frac{5 \: g}{56 g/mol} [/tex]
We have the final answer as
n = 0.089 molHope this helps you
[tex] \LARGE{ \boxed{ \pink{ \rm{Answer}}}}[/tex]
☃️ Chemical formulae ➝ [tex]\sf{CaO}[/tex]
How to find?For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
[tex] \boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}[/tex]
Solution:Atomic weight of elements:
Ca = 40O = 16❍ Molecular weight of [tex]\sf{CaO}[/tex]
= 40 + 16
= 56 g/mol
❍ Given weight: 5 g
Then, no. of moles,
⇛ No. of moles = 5 g / 56 g mol‐¹
⇛ No. of moles = 0.089 moles [tex]\approx[/tex] 0.09 moles
⚘ No. of moles of Calcium oxide in the given weight = 0.09 moles approx.
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I thought in the third shell there are 18 electrons, but why are they gaining only 2 electrons?? Pls tell me... I have exam tomorrow....
Which ionic equation for reaction of Magnesium with dilute hydrochloric acid is correct? Mg (s) + 2H+ (aq) â Mg2+ (aq) + H2 (g) Mg (s) + 2HCl (aq) â MgCl2+ (aq) + H2 (g) Mg (s) + 2H+ (aq) â Mg2+ (s) + H2 (g) Mg (s) + H+ (aq) â Mg+ (aq) + H2 (g)
Answer:
Mg(s) + 2H⁺(aq) ⟶ Mg²⁺(aq) + H₂(g)
Explanation:
A net ionic equation shows all the ionic substances as ions and shows the correct state of each substance.
B. is wrong. HCl ionizes in aqueous solution into H⁺ and Cl⁻.
C. is wrong. Mg²⁺ is not a solid. It is an aqueous ion.
D. is wrong. The equation needs 2H⁺(aq) to be balanced.
What must happen for water to boil at a given pressure?
O A. The water molecules must become more orderly.
O B. The water must gain thermal energy from its surroundings.
O C. The average kinetic energy of the water molecules must decrease.
D. The water must give off thermal energy to its surroundings.
Answer:
B. The water must gain thermal energy from its surroundings.
Explanation:
Boiling is the process whereby a substance is changed from a liquid state to a gaseous state due to the application of heat. For boiling to be achieved, a liquid substance must reach or exceed its boiling point, which is the specific temperature at which a specific liquid boils.
For this change of state i.e. from liquid to gas, to occur, atoms or molecules of the liquid must gain kinetic energy and move faster. However, this kinetic energy cannot be attained without a rise in temperature, which causes the molecules to gain THERMAL ENERGY or heat energy and move fast. Thermal energy is the energy that arises from a hot substance.
Therefore, for water to boil at a given pressure, it must gain thermal energy from its external surroundings, which causes its molecules to have an increased kinetic energy and move faster. This fast movement of the molecules causes the transition of phases (from liquid to gas).
A substance X contains 10 gram of calcium carbonate calculate the number of oxide of calcium carbonate present in x
Answer:
x contain 9 percent ofcalcium carbonaye
Electronic configuration is best described as
a. protons in the nucleus of atom
b. electrons on the outermost orbit
c. attraction of electrons between two atoms
d. arrangement of electrons in an atom
Answer:
d
Explanation:
The arrangement of electrons in an atom
Answer:
D. Arrangement of electrons in an atom.
Explanation:
K L M N O P Q
2 8 8 18 18 32 50
The path where electrons revolve is called orbits.
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1) what is formed when hydrogen burns ? write the equation for the reaction .
2) why do you think that, when hydrogen burns, the flame Rises quickly ?
Answer:
formed by burns rises quickly hydorogen
[tex] H_2+\frac12O_2 \longrightarrow H_2O[/tex]
I don't think I need to name the product.
this reaction is very exothermic. so the gases and the flames are very hot, i.e. very lighter (hot air rises) than the normal air. so it rises quickly
1. What are some of the steps to the scientific method?
Answer:
Observation.
Question.
Hypothesis.
Prediction.
Experiment.
Conclusion.
Explanation:
Make an observation about something.
Form a question about that thing.
Make a hypothesis.
Predict what will happen.
Experiment.
Draw a conclusion.
Answer:
These are some steps - it usually is listed with 5 basic steps. Feedback could be the additional step.
Explanation:
Make an observation. After you make an observation ask a question. Now you will be able to form your hypothesis - what is it that you are going to test? Now, you can make a predication based on the hypothesis that you created. Make sure to test the predictions that you make. Collect data. Check to see if others have done any work like you are collecting data on. Use data to make your final decisions - based upon the hypothesis and predictions that you made. If you get confused or lost - start again and change your hypothesis. Always, always, always reflect on your results. Make sure to use DATA to back up what you find.
Using the line graph below, find the independent and dependent variables.
I'll give brainliest.
Identify the goal of any scientific method
Answer:
Explanation:
Forming a testable hypothesis
Devising a study and collecting data
Examining the data and reaching conclusions
Reporting the findings of the study
Which series represents the flow of thermal energy in a home with a refrigeration cooling system?
Inside air coolant in cooling system – outside air
X Fuel
- air inside piston chamber piston movement
Inside air
outside air
Fuel
Inside air
Answer
A is the answer
Which criteria are responsible for deciding whether a heterogeneous mixture is a colloid or a suspension?
A.
whether its composition is uniform and transparent
B.
whether the particles remain suspended for an extended period of time
C.
whether it can be separated into simpler substances through physical separation techniques
D.
whether the ratio of components is fixed
Answer: C.
whether it can be separated into simpler substances through physical separation techniques
Explanation:
A heterogeneous mixture is colloidal if
Particles cannot be seen with a naked eye.Particles can pass through filter paperIt doesn't undergo sedimentation.A heterogeneous mixture is suspension if
Particles can be seen with a naked eye.Particles cannot pass through filter paperIt undergoes sedimentation.So, the criteria are responsible for deciding whether a heterogeneous mixture is a colloid or a suspension is "whether it can be separated into simpler substances through physical separation techniques".
So, the correct answer is "c".
Molar mass is reported on the periodic table in the units
A. kg/m3
B. grams/mole.
C. moles/gram.
D. atoms/gram.
Answer:
[tex]\boxed{\sf B. \ grams/mole}[/tex]
Explanation:
[tex]\sf The \ molar \ mass \ of \ a \ substance \ is \ the \ mass, \ in \ grams,\ per \ one \ mole.[/tex]
[tex]\displaystyle \sf \frac{grams}{mole}[/tex]
Answer:
B
Explanation:
Grams/mole is correct. Got right on test!
Over a long period of time, a group of people were exposed to high degrees of UV radiation from the sun. While no one became sick immediately, doctors did predict that those exposed had an increased risk of cancer in skin cells. Which type of mutation will this exposure cause? A. acquired, harmful B. acquired, neutral C. inherited, beneficial D. inherited, neutral
Answer:
acquired/harmful
Explanation:
This type of mutation and exposure will cause indefinite problems.
When does a solar Eclipse happen, and how?
Answer:
Solar Eclipse happens when the moon gets between the sun and the earth, the moon gets all the light and blocks the earth from getting sunlight.
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Which of these is the definition of the EXPLODE Physical Hazard?
A) Chemicals that are likely to be flammable and/or support a fire
B) Chemicals that release high pressure and could cause bodily injury
C) This is a potential reaction that could take place when two chemicals are
mixed together.
D) This is when a chemical breaks down and could become harmful when
handled improperly or exposed to extreme temperatures
Answer:
Explanation:
Physical hazard means a chemical for which there is scientifically valid evidence that it is a combustible liquid, a compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable (reactive) or water-reactive.
EXPLODE:
to expand with force and noise because of rapid chemical change or decomposition, as gunpowder or nitroglycerine (opposed to implode).
to burst, fly into pieces, or break up violently with a loud report, as a boiler from excessive pressure of steam.