Answer:
The correct answer choice is A. A chemical change has occurred because new compounds have been produced.
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.Example: Melting of ice A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.Example: photosynthesis
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.
Thus the true statement is a chemical change has occurred because new compounds have been produced.
How/ why does weather "happen," on Earth?
aused by the weight of the huge numbers of air molecules that make up the atmosphere. ... When air pressure is low, air flows together and then upward where it converges, rising, cooling, and forming clouds.
Answer:
Explanation:
The weather events happening in an area are controlled by changes in air pressure. Air pressure is caused by the weight of the huge numbers of air molecules that make up the atmosphere. ... When air pressure is low, air flows together and then upward where it converges, rising, cooling, and forming clouds.
Explain in terms of chemical reactivity why the elements in group 18 on the modern periodic table were not identified by Mendeleev's at that time
Answer:
elements tend not to react with other elements, there were no oxide compounds for Mendeleev to study. –Group 18 elements are generally unreactive. sodium ion is smaller because the sodium atom lost one electron. –An Na+ ion is smaller because it has one fewer electron shell.
Explanation:
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Also have a great day and good luck in your studies!
AgNO3 is a useful chemical that has many applications and can undergo a variety of reactions. In the following examples, balance each equation if necessary and then identify what type of reaction it represents. i. AgNO3 + Cu —>Cu(NO3)2 + Ag ii. AgNO3 —> Ag +O2 + NO2 iii. AgNO3 + KCI —> AgCI + KNO3 iv. Ag+ +I- +Agl
The balance chemical equation and the type of reaction of AgNO₃ and the other compounds can be represented as follows;
2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag (single displacement )
2AgNO₃ → 2Ag + O₂ + 2NO₂ (decomposition reaction)
AgNO₃ + KCI → AgCI + KNO₃(double displacement reaction)
2Ag + I₂ → 2AgI (synthesis reaction)
AgNO₃ + Cu → Cu(NO₃)₂+ Ag
The balance equation is as follows:
2AgNO₃ + Cu → Cu(NO₃)₂ + 2AgThis is a single displacement (substitution) reaction. The Copper substance displaced silver from it compound.
AgNO₃ → Ag + O₂ + NO₂
The balance equation is represented as follows:
2AgNO₃ → 2Ag + O₂ + 2NO₂The reaction is a decomposition reaction. Silver nitrate was decompose to it individual constituent.
AgNO₃ + KCI → AgCI + KNO₃
The balance equation is represented as follows:
AgNO₃ + KCI → AgCI + KNO₃The reaction is a double displacement reaction. The anions and cations of two different compound switch places, forming two entirely different compounds.
Ag + I₂ → AgI
The balance equation is as follows:
2Ag + I₂ → 2AgIThe reaction is a synthesis reaction. The individual elements combined to form a compound.
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describe the atomic models above in terms of
a. location of nucleus
b.location of electrons
Elements with ________ atomic mass are best possible candidates for a fusion reaction. very low moderate to heavy moderate very heavy
very low
Explanation:
Nuclear fusion is a nuclear reaction wherein small nuclei are combined to form heavier nuclei. This process constantly occurs in the sun, which is mainly composed of hydrogen and helium atoms.
Which best defines color? (1 point)
a physical property of matter related to how a material interacts with different wavelengths
of light
a chemical property of matter related to how a material interacts with different wavelengths
of light
O a physical property of matter related to a material's ability to reflect light
O a chemical property of matter related to a material's ability to reflect light
Answer:
i believe the answer to your quetion will be A im on edge by the way so if your on a differnt program than it might be wrong sorry if im wrong have a wonderfull day!
Symbol of elements.
Explanation:
Gold Au
Copper Cu
Iron Fe
Magnesium Mg
Hydrogen H
Helium He
Mercury Hg
Iodine I
Acid hydrolysis of N-methylbutyramide in water and hydrochloric acid with heat produces______________________________.
a. Butyric acid and methylammonium chloride.
b. Butanoic acid and ammonium chloride.
c. Butanoate and methylamine.
Answer:
A- Butyric acid and methylammonium chloride.
Explanation:
Can someone please help. I have no idea how to do this
Explanation:
c-o number if electrons shared: 4. doubke bond. non polar
c-cl 2 electrons sharde single bond non polar
I know this cause one dash equals 2 electrons chemistry teachers use them when two compounds are sharing electrons rather then using two dots so people know the difference
What types of orbitals are found in the third energy level?
Answer:
1 s-orbital, 3 p-orbital and 5 d-orbital
Answer:
there are a total of nine orbitals in a third energy level
Explanation:
11) What volume will 0.75 mol of Oxygen gas (O2) occupy at 298 K and a pressure of 52.7 kPa?
Answer:
Volume = 35.3L
Explanation:
Use Ideal Gas Law (PV=nRT) and isolate for V (volume) by dividing both sides by P (pressure). You will then get the eqaution listed below and you can solve by using the method I used below.
V = nRT/P
V = (0.75kPa)(8.314)(298K)/(52.7kPa)
V = 1858.179/52.7
V = 35.3L
Identify one cause of the loss of forests that is not intentional.
Answer:
Natural causes are unintentional.
Explanation:
An example would be a wildfire. This natural disaster spreads quickly, especially in forests where wood burns easily. Destroying forests through burning causes nutrients to get depleted, and organisms die.
Which of the following is not part of an amino acid?
A. ammonium group
B. carboxylate group
C. ether group
D. unique "R" group
Answer:
C
Explanation:
Ether group does not exist in amino acids
Ammonium group is on one side
the carboxylate group is opposite to the ammonium group
the R group defines what amino acid it is.
Diazene, N2H2 (also known as diimine), is commonly used as a reagent for organic syntheses. Label each image with the type of
bond in diazene that it shows.
The first image shown at the left hand side is a pi bond. The other two images show sigma bonds.
In chemistry, a bond results from the overlap of atomic orbitals. This overlap may be end to end (sigma bond) or side by side (pi bond). Having said this, it is easier to decide whether the bonds in the image shown are sigma or bi bonds.
If we label the images; 1,2,3 from left to right, we can see that the overlap in image 1 is side by side. The electron density lies above and below the plane of the bond. This is a pi bond. In images 2 and 3, the overlap occurs in an end to end manner. This is a sigma bond.
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How many decigrams of chromium are in 3.19 x 10^23 atoms of chromium? show work
mol = 3.19 × 10^23/6.02^23
= 0.529 mol
mass = 0.529 × 52
= 27.508 g
g to decigram
= 27.508 × 10
= 275.08 decigram
Sort the sentences based on whether they describe the properties of a heterogeneous or a homogenous mixture.
Answer:
Carbonate Sodium Hydrogen
How many ml of a 2.903 M NaOH solution are needed to produce 500.0 ml of a 0.3344M solution?
Answer:
57.6ml
Explanation:
Using dilution formula
C1V1 = C2V2
C1 = 2.903 M, V1 = ? , C2 = 0.3344 M , V2 = 500ml
2.903 × V1 = 0.3344 × 500
V1 =( 0.3344 × 500)/ 2.903
= 57.5956
≈ 57.6ml
The Planet Venus is surrounded by a thick layer of gases. In fact the atmospheric preassure on Venus is over 90 times grater than the atmospheric preassure on Earth. Wcich statements are true about boiling water on Venus? Choose the TWO STATEMENTS that aply.
A. Water will boil at a higher temperature on Venus than on Earth.
B. Water will boil at a lower temperature on Venus than on Earth.
C. The temperature of the water will remain constant as it boils.
D. The temperature will increase as it boils.
Which is better Epoxy or Super Glue?
Answer:
Personally, I use Superglue
Explanation:
The balanced chemical equation for the conversion of nitrogen to ammonia is:2N₂(g) + 3H2(g)2NH3(g): Which of the following statements concerning this chemical equation is/are correct?
1. In a 22.4 L container at standard temperature, 2 atm of nitrogen gas will react with 3 atm of hydrogen gas to produce 2 atm of ammonia gas.
2. At standard pressure and temperature, 22.4 L of nitrogen gas will react with 22.4 L of hydrogen gas to produce 22.4 L of ammonia gas.
3. At standard pressure and temperature, 44.8 L of nitrogen gas will react with 67.2 L of hydrogen gas produce
22,4 L of ammonia gas
Answer:
At standard temperature and pressure, 44.8
Explanation:
What is the interaction between geosphere and biosphere
Answer:
The Geosphere interacts with the Biosphere in various ways. For example; Geosphere creates, destroys and keeps various biosphere habitats safe. The Geosphere interacts with the Cryosphere in various ways. For example; Cryosphere receives snow from hydrosphere, glacier of Cryosphere gouges geosphere.
Explanation:
The Geosphere interacts with the Biosphere in various ways. For example; Geosphere creates, destroys and keeps various biosphere habitats safe. The Geosphere interacts with the Cryosphere in various ways. For example; Cryosphere receives snow from hydrosphere, glacier of Cryosphere gouges geosphere.
What is the molarity of a NaOH solution when 22.14 mL of 0.105 M oxalic acid is needed to
neutralize 25.0 mL of the base.
The molarity of the NaOH solution required for the reaction is 0.186 M
We'll begin by writing the balanced equation for the reaction
H₂C₂O₄ +2NaOH —> Na₂C₂O₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂C₂O₄ (nA) = 1
The mole ratio of the base, NaOH (nB) = 2
From the question given above, the following data were obtained:
Volume of the acid, H₂C₂O₄ (Va) = 22.14 mL
Molarity of the acid, H₂C₂O₄ (Ma) = 0.105 M
Volume of the base, NaOH (Vb) = 25 mL
Molarity of the base, NaOH (Mb) =?MaVa / MbVb = nA/nB
(0.105 × 22.14) / (Mb × 25) = 1/2
2.3247 / (Mb × 25) = 1/2
Cross multiply
Mb × 25 = 2.3247 × 2
Mb × 25 = 4.6494
Divide both side by 25
Mb = 4.6494 / 25
Mb = 0.186 MTherefore, the molarity of the base, NaOH solution is 0.186 M
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need help with question please ..
-20 points
Answer:
B oklolol
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Explain why the first ionisation energy of beryllium is higher than the first ionisation
energy of lithium.
Answer:
since the distance between the electron and the nucleus is smaller in B than in Li, the electrostatic nuclear force of attraction experienced by B is higher than the one experienced by Li...this translates to the higher first ionization energy in B than in Li.
Explanation:
i hope it's helping!
In the urea molecule, (NH2)2CO, both nitrogen atoms are bonded to the carbon atom. Each nitrogen atom has a lone pair. The molecular geometry is
Answer:
There are two -NH2 groups around the C=O. bond in the urea molecule structure. There are one lone pairs on each nitrogen atoms and two lone pairs on oxygen atom.
The molecule urea that the molecular geometry of the nitrogen atoms is tetrahedral.
What is molecular geometry?The term molecular geometry has to do with the arrangement of atoms around the central atom. On this case, we are looking at the arrangement of atoms around nitrogen.
We can see from the molecule urea that the molecular geometry of the nitrogen atoms is tetrahedral.
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Which pair of elements form an ionic bond with
each other?
A. KCL
B. ICL
C. PCL
D. HCL
I think it’s A and D but if it’s not both can you please explain why it’s one and not the other?
Answer:
Yes Both A) KCL and D) HCL are correct...
Answer:
It's only A
Explanation:
Potassium (K) is a metal and Chlorine (Cl) is a nonmetal, and ionic compounds are formed between metals and nonmetals. So KCl forms ionic bonds.
Hydrogen (H) and Chlorine (Cl) are both nonmetals, and only covalent bonds form between nonmetals. (Only exception is when its an acid, then it's ionic)
Also, the question indicated which "pair" and not "pairs" meaning that there is only one answer, and I'm more likely to go with A rather than D.
A team of scientists is conducting tests to measure the boiling point of a liquid using a thermometer in the liquid. The team is
then recording the temperature where the liquid changes from a liquid to a gas rapidly. After 100 trials, the results are 5 degrees
below the expected results. Which next step is most reasonable? (1 point)
O checking the calibration of the thermometer to ensure that it is giving accurate readings
O assuming that the new results are incorrect
O assuming that the previous measurements are incorrect
O checking the insulation of the apparatus to find out if heat is escaping
The most reasonable step to take will be to check the calibration of the
thermometer to ensure that it is giving accurate readings.
Experiments which are done to be give the same results under standard
conditions. Common causes of incorrect results during the analysis of
boiling point of substances include heating the substance too rapidly or
the thermometer not being properly calibrated.
The thermometer is used to measure the temperature and so must be
properly calibrated to give accurate readings.
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Which of the following best describes the arrangement of particles in a gas?
O The particles are spread apart and can move freely.
O The particles are packed closely together and can move freely.
O The particles are packed closely together and cannot move freely
O The particles are spread apart and cannot move freely.
Answer: The particles are spread apart and can move freely.
An aqueous solution was prepared by dissolving 266.07 g of AgNO3 ( 169.88 g/mol) in enough water to make a total volume of 250.0 ml. What is the molarity of the solution
Answer:
The correct answer is 6.265 M.
Explanation:
To find the molarity of the solution, we first must recall that molarity represents the number of moles of solute divided by the number of liters of solution. Thus, our first step should be to convert the solute amount in grams to moles, using the given molar mass.
266.07 g * (1 mol/169.88 g) = 1.5662 mol
Now, we can find the molarity using the following formula:
Molarity = moles solute/liters solution
M = 1.5662 mol/0.25 L
M = 6.265 M
Therefore, the molarity of the solution is 6.265 M.
Hope this helps!
9 Select the correct answer. Which statement correctly describes a physical change? O A involves breaking and creating chemical bonds but not changing a phase OB. may involve a change in phase but does not involve a change in the molecular structure OC. may involve converting two or more substances into new substances OD. involves changes at the molecular level O E. involves energy transfer and change in color Reset Next
Answer: The statement that correctly describes a physical change is may involve a change in phase but does not involve a change in the molecular structure. The answer is letter B.
Explanation: trust me
Explanation:
OA- because there is breakdown of chemical bonds