The answer is c. Matter can be changed, but not created or destroyed.
The amount of energy needed to change a liquid to a solid is calculated using the enthalpy of ________ and has a __________ sign on the energy value.
the valence electrons of metals jump easily to a higher energy orbital when light shines on them then they all fall emiting the excess energy as light which property of metals is explained by this?
Answer:
Lustrous
Explanation:
Metals are lustrous which gives them a property of having Shiny surfaces
The valence electrons of metals jump easily to a higher energy orbital when light shines on them then they all fall emitting the excess energy as light show lustrous property of metals.
What are valence electrons?Valence electrons are defined as a negatively charged particle that can be shared or transmitted between atoms that is found in the outermost shell of an atom. Valence electrons have a crucial role in determining how an atom will behave. The electrical configurations of elements can be used to find valence electrons. The total number of valence electrons in that element is then determined by counting the number of electrons in the outermost shell.
When newly treated, polished, or broken, a material takes on a bright look and conducts electricity and heat reasonably well. Metals are typically ductile and malleable. These traits are the result of the metallic bond that connects the atoms or molecules of the metal.
Thus, the valence electrons of metals jump easily to a higher energy orbital when light shines on them then they all fall emitting the excess energy as light show lustrous property of metals.
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I am having the worst day ever, Someone please cheer me up. :( I'll mark you as brainiest. :(
Once I told a chemistry joke
I got no reaction.
What do you do with a sick chemistry teacher?
If you can't helium, and can't curium, you might as well barium.
I don't trust atoms,
I heard they make up everything
Hope I helped make ur day. :)
in which time period did the first animals that could live both in water and on land appear
How many moles of nitrogen dioxide, NO2, are present if the reaction conditions are 330 K, 2.46 atm, and 4.8 L
There are 0.436 moles of nitrogen dioxide, NO2, present if the reaction conditions are 330 K, 2.46 atm, and 4.8 L.
IDEAL GAS LAW:The number of moles of nitrogen dioxide (NO2) in this question can be calculated by using the ideal gas law equation as follows:
PV = nRT
Where;
P = pressure (atm)V = volume (L)T = temperature (K)R = gas law constant (0.0821 Latm/molK)n = number of molesAccording to the reaction conditions given in this question;
P = 2.46 atmV = 4.8Ln = ?T = 330K2.46 × 4.8 = n × 0.0821 × 330
11.81 = 27.093n
n = 11.81 ÷ 27.093
n = 0.436mol
Therefore, there are 0.436 moles of nitrogen dioxide, NO2, present if the reaction conditions are 330 K, 2.46 atm, and 4.8 L.
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Static electricity is a ____ charge.
A. permanent
B. missing
C. flowing
D. temporary
How is a chemical equation different from mathematical equation?
Only chemical equation uses + sign
Only chemical equation uses arrow instead of = sign
Only chemical equation has numbers
Only chemical equation has minuses
Answer:
Only chemical equation uses arrow instead of = sign
Answer:
Only chemical equation uses an arrow instead of a = sign.
A chemical equation depicts a chemical reaction by utilising chemical formulae and symbols to depict the reactants, products, and chemical changes that take place. In a chemical equation, the arrow indicates the direction of the reaction and is commonly depicted as a single arrow pointing from the reactants to the products. In contrast, the equals sign (=) is commonly used in mathematical equations to indicate that two expressions have the same value.
While numbers are used to indicate the relative proportions of reactants and products and minus signs are used to indicate reactants or products in the form of ions, the arrow is the most distinguishing feature that distinguishes chemical equations from mathematical equations.
PC13 ionic or covalent
Answer:
The bond between Phosphorus and Chlorine in PCl3 is covalent as chlorine needs one electron and phosphorus has metallic character and easily donate electron
Do solar panels use electrical energy or produce electrical?
Answer:
How Does a Solar Panel Generate Power? Solar panels use the photons produced by sunlight to generate direct current (DC) electricity. When the photons hit the panel they are absorbed by the panel's semiconducting silicon material.
Explanation:
Answer:
Solar panels produce electrical energy by absorbing the solar energy from the sun and converting it into electrical energy.
Explanation:
Please Help! (Will mark brainliest)
How many chlorine atoms are in 4 moles of chlorine?
A sample of acetaminophen has 100,000 molecules in it.
Answer:
2.409*10^24
Explanation:
If I am not mistaken you are supposed to do 4*6.022*10^23. This will allow for it to be converted.
I hope this helped
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HURRY I HAVE 20 MIN LEFT will mark brainllest When. Coach Kwan notices that a player is getting tired, she takes out the tired player and substitutes a fresh player. Which type of chemical reaction does this best model?
replacement
decomposition
synthesis
oxidation
Which molecule has ionic bond?
Mg
C0
NaCl
N0
NaCl - Chlorine has an outer shell with 7 electrons it wants to gain from the Sodium to become stable, whereas the Sodium wants to lose an electron to become stable.
If two atoms have an electronegativity difference of 1.3, what type of bond would form between them?
Select one:a. non polar covalent b. polar covalent. c. ionic
Answer:
I would say iconic bond
Explanation:
In the following experiment, a coffee-cup calorimeter containing 100mL OF H2O is used.
Please provide more of the question so I am able to answer, but I do know that H20 has 0 calories.
Polyester is a synthetic material used for many different purposes. It is produced from petroleum and natural gas. Producing polyester from these natural resources requires many steps and uses other chemicals that are potentially harmful. Polyester production also requires a lot of energy. Although polyester is not biodegradable, it is easily recyclable.
Which statement about synthetic materials is best supported by the example of polyester?
A.
Using synthetic materials has a negative impact on the environment, but using natural materials does not.
B.
Synthetic materials created from petroleum and natural gas are difficult to produce and to recycle.
C.
Materials that are created from natural resources affect the environment more than those that are not.
D.
Producing certain synthetic materials could have a greater environmental impact than disposing of them.
Answer:
A. Producing certain synthetic materials could have a greater environmental impact than disposing of them.
Explanation
I just did this question and got it right.
I need help with stoichiometry
Which of the following is the correct way to do it for 3753 Scientific notation
Answer:
b
Explanation:
it is b because it has 4 spots and that would be 3 zeros so it is to the 3rd power
How many grams of potassium sulphate are formed when 49g of sulphuric acid in solution are neutralised by potassium hydroxide?
If 12.7 grams of hydrogen reacted with an unknown amount of oxygen, how many grams of water would be produced? (Write a balanced equation and show your work under the equation)
Answer:
2H2 + 1 O2 ------> 2H2O
m = 12.7g m = ?
Get the number of moles for Hydrogen gas (H2) by dividing the mass by the molar mass (1.01g/mol as listed in the periodic table for its atomic mass)
12.7/1.01 = 12.57 mol of H2
Now use the mole to mole ratio of Hydrogen gas (H2) and water (H2O).
From the balanced equation, we can see that 2 mol of H2 gives us 2 mol of H2O. Since both of the ratios are equal (2:2), the moles we have for hydrogen gas is the same as the moles we get for water.
12.57 mol of H2O
Now that we have the amount of mol for H2O produced in this reaction, we can convert it to grams by multiplying the moles by the molar mass.
Molar mass of H2O = (1.01 x 2) + (16) = 18.02g/mol
12.57 x 18.02 = 226.5g (rounded)
Therefore 226.5g of water will be produced in this reaction
According to law of conservation of mass and stoichiometry, 114.3 g of water are produced if 12.7 grams of hydrogen reacted with an unknown amount of oxygen.
What is law of conservation of mass?According to law of conservation of mass, it is evident that mass is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.
2 H₂ + O₂[tex]\rightarrow[/tex] 2 H₂O,according to this equation,4 g hydrogen reacts with 32 g oxygen to give 36 g water, thus 12.7 g of hydrogen will produce 12.7×36/4=114.3 g water and hence for this amount of water to be formed 12.7 g of hydrogen reacts with 101.6 g of oxygen which is obtained as 114.3-12.7=101.6 g
Thus, 114.3 g of water is produced.
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explain the concept of thekinetic molecular theory
Answer:
Kinetic Molecular Theory states that gas particles are in constant motion and exhibit perfectly elastic collisions. Kinetic Molecular Theory can be used to explain both Charles' and Boyle's Laws. The average kinetic energy of a collection of gas particles is directly proportional to absolute temperature only.
Explanation:
hope this helps! goodluck & enjoy the rest of ur day or night.
This chemical equation is balanced.
F2 + 2NaBr
2NaF + Br2
How does the balanced chemical equation show the conservation of matter
in this chemical reaction?
A. There are fewer Na atoms in the reactants than in the products.
B. The number of Fatoms in the reactants equals the number of F
atoms in the products.
C. The compound NaF is a substance that is different from the
compound NaBr.
D. There are more Br atoms in the reactants than in the products.
what sea animals have moveable spines that they use for protection
Answer:
sea urchins
Explanation:
Answer:
sea urchins
Explanation:
i took the test
the bradford assay only works at low protein concentrations
Answer:
Dilute the sample
Explanation:
The statement is not entirely accurate. The Bradford assay is commonly used to determine protein concentrations in a sample.
However, it is true that the Bradford assay is more accurate and reliable for measuring protein concentrations at low to moderate levels rather than at very high concentrations.
The Bradford assay is based on the binding of Coomassie Brilliant Blue dye to proteins. The dye undergoes a color change from brown to blue when bound to proteins, allowing for the measurement of protein concentrations. At low protein concentrations, the binding of the dye to proteins is well-calibrated and results in a linear relationship between protein concentration and color intensity, making it suitable for accurate quantification.
At high protein concentrations, the binding capacity of the dye may become saturated, leading to non-linear and less accurate measurements. The excess protein can also cause interference and affect color development. In such cases, dilution or alternative protein quantification methods may be more suitable, such as the BCA assay or the Lowry assay.
Therefore, while the Bradford assay can be used to measure protein concentrations across a range of concentrations, it is generally more reliable for low to moderate protein concentrations.
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I’m in science class right now and I need help on these questions
Answer:
hello
Explanation:
please help quickly
Rubia was given a type of inclined plane called a ramp in her science class. Her teacher told her that the ramp should have a mechanical advantage of 3.
Rubia pulled a block up the ramp, but afterward she calculated that the mechanical advantage of the ramp was 2.8 instead of 3. Her teacher said she did not make a mistake. What did Rubia calculate?
A.
the actual operating power of the ramp
B.
the actual mechanical advantage of the ramp
C.
the ideal mechanical advantage of the ramp
D.
the ideal operating power of the ramp
Answer: B. The actual mechanical advantage of the ramp.
Explanation:
The professor saying that the ramp SHOULD have a mechanical advantage of 3 indicates that that would be the ideal mechanical advantage. Since Rubia calculated it to be 2.8, that means that it is the acutal mechanical advantage. The actual advantage will be reduced from the ieal due to things like friction.
250 mL of argon gas is held in a flexible vessel shown above. If
the pressure changes to 12.0 atm, what is the new volume of
the gas at 20°C?
The new volume of the gas at 20 °C is 205 mL
From the question given above, the following data were obtained:
Initial volume (V₁) = 250 mL Initial pressure (P₁) = 10 atmInitial temperature (T₁) = 25 °C = 25 + 273 = 298 KNew pressure (P₂) = 12 atmNew temperature (T₂) = 20 °C = 20 + 273 = 293 KNew volume (V₂) =?With the application of the combine gas equation, we can obtain the new volume of the gas as illustrated below:
[tex]\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2} \\ \\ \frac{10 \times 250}{298} = \frac{12 \times V_2}{293} \\ \\ \frac{2500}{298} = \frac{12 \times V_2}{293} \\ \\ cross \: multiply \\ \\ 298 \times 12 \times V_2 = 2500 \times 293 \\ \\ divide \: both \: side \: by \: 298 \times 12 \\ \\ V_2 = \frac{2500 \times 293}{298 \times 12} \\ \\ V_2 = 205 \: mL \\ [/tex]
Therefore, the new volume of the gas is 205 mL
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The new volume of the gas at the given pressure and temperature is 205 mL.
The given parameters:
Initial volume of argon, V₁ = 250 mLInitial pressure of gas, P₁ = 10 atmFinal pressure of the gas, P₂ = 12 atmInitial temperature of the gas, T₁ = 25 ⁰C = 273 + 25 = 298 KFinal temperature of the gas, T₂ = 20 ⁰C = 273 + 20 = 293 KThe new volume of the gas is calculated by applying general gas equation as follows;
[tex]\frac{V_1 P_1}{T_1} = \frac{V_2P_2}{T_2} \\\\V_2 = \frac{V_1P_1 T_2}{T_1P_2} \\\\V_2 = \frac{(250\ mL) \times 10 \times 293}{298 \times 12} \\\\V_2 = 204.84 \ mL\\\\v_2 = 205 \ mL[/tex]
Thus, the new volume of the gas at the given pressure and temperature is 205 mL.
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the boiling point of water at standard pressure is
Answer:
100 Celsius mostly because water boils at sea level
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?
The sodium ion is negative, and the hydroxide ion is positive.
The sodium ion is positive, and the hydroxide ion is positive.
The sodium ion is positive, and the hydroxide ion is negative.
The sodium ion is neutral, and the hydroxide ion is neutral
The two ions present in the solution are:
1. Sodium ion, Na⁺
2. Hydroxide ion, OH¯
The correct answer to the question is the 3rd option. The sodium ion is positive, and the hydroxide ion is negative.
Ions are atoms or group of atoms which possess an electric charge.
Aqueous Sodium hydroxide, NaOH contains sodium ion and hydroxide ion.
The sodium ion is positive while the hydroxide ion is negative as illustrated below:
NaOH(aq) —> Na⁺(aq) + OH¯(aq)
From the illustration above, we can conclude that the correct answer to the question is the 3rd option. The sodium ion is positive, and the hydroxide ion is negative.
Please see attached photo for further details
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How many grams are in 3.4 moles of Lead (IV) Sulfate (Pb(SO4)2)? ) Molar mass: 303.26 g/mol 131.0840
Answer:
1031.084g
Explanation:
n=m/M
m=n(M)
m = (3.4mol)(303.26g/mol)
1031.084g
Hope that helps
Answer:
1031.08
Explanation:
You start with 3.4 moles and you know that 6.022 x 10 ^ 23 = 1 mole( Avogadro's Number), so you just multiply those 2 numbers and the moles will cancel leaving you with grams of Lead Sulfate.