Answer:
d. ii and iii
Explanation:
Both the Bohr model and the wave (quantum) mechanical models of the atom recognize the principal quantum number n. The principal quantum number shows the shell or energy level where an electron may be found.
The energy levels are arranged in increasing order of magnitude. That is n=1 >n=2=n=3 etc
Four different methods are described for validating the results of a particular analysis. Indicate for each whether the method primarily checks the accuracy of the analysis or the precision of the analysis. Method 1: Five aliquots of the same sample are injected for a gas-chromatographic analysis by one person on the same day. a. precision.b. accuracy.Method 2: A known amount of analyte is added to an aliquot of the sample and analyzed with the sample. a. precision.b. accuracy. Method 3: Aliquots from a blood sample are sent to three separate laboratories for analysis using the same method. a. precision.b. accuracy. Method 4: Identical standards are analyzed by two different methods. a. accuracy.b. precision.
Answer:
Method 1 - precision
Method 2 - accuracy
Method 3 - precision
Method 4 - accuracy
Explanation:
The accuracy of a method refers to how close the experimental result is to the accepted value. Accuracy could be checked by carrying out the required test on the standard and not on the sample or by adding a known amount of analyte to the sample so that the results obtained can be carefully compared.
Precision on the other hand, refers to how close the results of a replicate analysis are to each other. In testing for precision, the analysis must be carried out several times, in order to check how close the results are to each other.
Determine the milliliters of paint in a 5.0 gallon bucket
Ans: 18950 ML
Answer:
the answer is 18,927,06.
Explanation:
I just took the test ; )
How many moles of carbon are produced When 1745g of sugar react according to the equation C6H12O6+ H2SO4 to 6C +6H2O
Answer:
Number of moles of C produced = 58.08 mol
Explanation:
Given data:
Mass of sugar = 1745 g
Moles of C produced = ?
Solution:
Chemical equation:
C₆H₁₂O₆ + 6H₂SO₄ → 6C + 6(H₂SO₄.H₂O)
Number of moles of sugar:
Number of moles = mass/molar mass
Number of moles = 1745 g/180.16 g/mol
Number of moles = 9.68 mol
Now we will compare the moles of C and sugar.
C₆H₁₂O₆ : C
1 : 6
9.68 : 6×9.68 = 58.08 mol
Number of moles of C produced = 58.08 mol
Match the term with the definition. (4 points)
Column A
1.
Liquid
:
Liquid
2.
Plasma
:
Plasma
3.
Solid
:
Solid
4.
Gas
:
Gas
Column B
a.
has lots of space between the charged particles
b.
has lots of space between particles and is easily compressible
c.
flows easily but is difficult to compress
d.
does not flow easily and is difficult to compress
Answer:
1 - does not flow easily and is difficult to compress
2 -does not flow easily and is difficult to compress.
3 -has lots of space between the charged particles.
4-flows easily but is difficult to compress.
Explanation:
What is the smallest particle of matter called?
Answer:
an atom and inside the atom are protons electrons and nuetrons
Explanation:
Answer:
An Atom
Explanation:
An atom is the most smallest particle of matter, you can't see with the most powerful telescopes or microscopes
PLEASEEEEEEEEEEEEEEEEEEEE im slow i'll give you brainliest if you answer idkk what to do
a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
Compound:A compound is a material formed by chemically bonding two or more chemical elements. The type of bond keeping elements in a compound together may vary: covalent bonds and ionic bonds are two common types. The elements are always present in fixed ratios in any compound.
Element:Chemical element, also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.
Mixture:is a material made up of two or more different substances which are physically combined.
Chemical Formula:A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. I
Pure substance:A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen.
hope this help!
Answer:
Here are the definitions of all of them.
Explanation:
Molecule:
a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
Compound:
A compound is a material formed by chemically bonding two or more chemical elements. The type of bond keeping elements in a compound together may vary: covalent bonds and ionic bonds are two common types. The elements are always present in fixed ratios in any compound.
Element:
Chemical element, also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.
Mixture:
is a material made up of two or more different substances which are physically combined.
Chemical Formula:
A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. I
Pure substance:
A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen.
Suppose 4.0 g of hydrogen reacts completely with 32.0 g of oxygen to form one product what is the mass of the product?
Answer: The mass of product, [tex]H_2O[/tex] is, 36.0 grams.
Explanation : Given,
Mass of [tex]H_2[/tex] = 4.0 g
Mass of [tex]O_2[/tex] = 32.0 g
Molar mass of [tex]H_2[/tex] = 2 g/mol
Molar mass of [tex]O_2[/tex] = 32 g/mol
First we have to calculate the moles of [tex]H_2[/tex] and [tex]O_2[/tex].
[tex]\text{Moles of }H_2=\frac{\text{Given mass }H_2}{\text{Molar mass }H_2}[/tex]
[tex]\text{Moles of }H_2=\frac{4.0g}{2g/mol}=2.0mol[/tex]
and,
[tex]\text{Moles of }O_2=\frac{\text{Given mass }O_2}{\text{Molar mass }O_2}[/tex]
[tex]\text{Moles of }O_2=\frac{32.0g}{32g/mol}=1.0mol[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical equation is:
[tex]2H_2+O_2\rightarrow 2H_2O[/tex]
From the balanced reaction we conclude that
2 mole of [tex]H_2[/tex] react with 1 mole of [tex]O_2[/tex]
From this we conclude that, there is no limiting and excess reagent.
Now we have to calculate the moles of [tex]H_2O[/tex]
From the reaction, we conclude that
2 moles of [tex]H_2[/tex] react to give 2 moles of [tex]H_2O[/tex]
Now we have to calculate the mass of [tex]H_2O[/tex]
[tex]\text{ Mass of }H_2O=\text{ Moles of }H_2O\times \text{ Molar mass of }H_2O[/tex]
Molar mass of [tex]H_2O[/tex] = 18 g/mole
[tex]\text{ Mass of }H_2O=(2.0moles)\times (18g/mole)=36.0g[/tex]
Therefore, the mass of product, [tex]H_2O[/tex] is, 36.0 grams.
What would be the formal charge of N in NO2?
Answer:
What would be the formal charge of N in NO2?
Explanation:
The nitrogen gets two electrons for the double bond, one from the single bond and one from the half-filled orbital associated with it. That's a total of 4 and gives N a +1 formal charge since itneeds 5 to be neutral. The Rules for Writing Lewis Structures has some discussion of formal charge in it.
Help!!!
A. A halogen
B. An alkaline earth metal
C. An alkali metal
D. A transition element
Answer:
B?
Explanation:
How much heat is required to raise the temperature of 93.5 gg of water from its melting point to its boiling point
Answer:
39270 J
Explanation:
The quantity of heat required to raise the temperature of a substance from its initial temperature to its final temperature is given by:
Q = mCΔT
m = mass of substance, C = specific heat capacity of substance, ΔT = temperature change = final temperature - initial temperature
Melting point = 0°C, boiling point = 100°C, m = 93.5 g = 0.0935 g, ΔT = boiling point - melting point = 100 - 0 = 100°C, C = 4200 J/kg°C
Q = mCΔT
Q = 0.0935 × 4200 × 100 = 39270 J
Element Rand Element Q have the same number of valence
electrons. These elements both have similar chemical behavior, but
Element R has fewer energy levels than Element Q. Which statement best
describes the positions of the two elements in the periodic table?
I know I'm answering super late, but I just want to help others who don't know the answer
Answer:
H. The two elements are in the same group, with Element R just above Element Q.
Explanation:
When answering a question like this, I would highly recommended using a periodic table. I used a periodic table to find the answer to the question.
Classify the sugars as either aldoses or ketoses. A Fischer projection with a six carbon backbone. Carbon one is an aldehyde and carbon six is part of the group C H 2 O H. Carbons two and three have an hydroxide group on the left, and carbons four and five have an hydroxide group on the right. A Fischer projection of a six carbon backbone. Carbons one and six are part of a C H 2 O H group. Carbon two is attached to a ketone, carbons three and four have a hydroxide group on the left, and carbon five has a hydroxide group on the right. A Fischer projection with a five carbon backbone. Carbon one is an aldehyde, carbon five is part of the group C H 2 O H, and carbons two through four have an hydroxide group on the right. A Fischer projection with a three carbon backbone. Carbon one is an aldehyde, carbon three contains the group C H 2 O H, and carbon two has a hydroxide group on the right. A Fischer projection with a five carbon backbone. Carbons one and five are part of a C H 2 O H group. Carbon two is attached to a ketone and carbons three and four have a hydroxide group on the right. A Fischer projection of a four carbon backbone. Carbons one and four are part of a C H 2 O H group. Carbon two is attached to a ketone and carbon three has a hydroxide group on the right. Answer Bank
Answer AND Explanation: Carbohydrates or sugars have three classes:
Monossaccharides: made from a single polyhydroxy aldehyde or ketone unit;Oligosaccharides: formed by short chains of monossacharides united by glycosidic linkage;Polysaccharides: consist of a long chain of monossaccharides;Monossaccharides are formed by a chain of unbranched carbon, all bonded by single bonds, except for a carbon that is double-bonded by an oxygen. This bond form a carbonyl group.
If the carbonyl is at an end of the chain, the carbon is aldehyde and the molecule is called aldose. If the group is in any other position, it is a ketone and is called ketose
So analysing each projection:
1) Carbon one is a aldehyde, which means is a carbonyl and there are no other carbons forming that bond, so it's a ALDOSE
2) Carbon two is attached to a ketone and other carbons aren't, so it's a KETOSE.
3) Carbon one is aldehyde, so it's ALDOSE
4) Carbon one is aldehyde, so ALDOSE
5) Carbon two is attached to ketone, so KETOSE
6) Carbon two attached to a ketone, so KETOSE
A 4.534 g sample of a solid mixture was analyzed for barium ion. First the rock was crushed in a mortar and pestle. 100% of the sample was transferred to a beaker, where it was dissolved in 150.0 mL of d.i. water. to give 152 mL of solution. The aqueous sample was then analyzed by adding a small excess of sulfuric acid. The resultant reaction produced a precipitate of barium sulfate, which was collected by filtration, rinsed, dried and weighed. If 0.5376 g of barium sulfate was obtained, what was the mass percent of barium in the original sample? What was the molar concentration barium in the 152 mL of solution prior to adding sulfuric acid? Show work clearly; include a balanced net ionic chemical equation, units and sig. figs.
Answer:
6.976%
0.0152 M
Explanation:
Step 1: Write the balanced chemical equation
Ba²⁺(aq) + H₂SO₄(aq) ⇒ BaSO₄(s) + 2 H⁺(aq)
The balanced net ionic chemical equation is:
Ba²⁺(aq) + SO₄²⁻(aq) ⇒ BaSO₄(s)
Step 2: Calculate the moles corresponding to 0.5376 g of BaSO₄
The molar mass of BaSO₄ is 233.39 g/mol.
0.5376 g × (1 mol/233.39 g) = 2.303 × 10⁻³ mol
Step 3: Calculate the moles of Ba²⁺ that produced 2.303 × 10⁻³ moles of BaSO₄
The molar ratio of Ba²⁺ to BaSO₄ is 1:1. The moles of Ba²⁺ are 1/1 × 2.303 × 10⁻³ mol = 2.303 × 10⁻³ mol.
Step 4: Calculate the mass corresponding to 2.303 × 10⁻³ moles of Ba²⁺
The molar mass of Ba²⁺ is 137.33 g/mol.
2.303 × 10⁻³ mol × 137.33 g/mol = 0.3163 g
Step 5: Calculate the mass percent of barium in the original sample
0.3163 g of barium ion were in a 4.534 g-sample. The mass percent of barium ion is:
0.3163 g/4.534 g × 100% = 6.976%
Step 6: Calculate the molar concentration barium in the 152 mL of solution
2.303 × 10⁻³ moles of barium ion were in 152 mL (0.152 L) of solution. The molarity of barium ion is:
M = 2.303 × 10⁻³ mol/0.152 L = 0.0152 M
Which of the following is least like the others on the list?
a. Glucose
b. Glycogen
c. Sucrose
d. Catalase
Answer:
catalase
Explanation:
catalase is enzime the rest are glucides
Enter the symbol of a sodium ion, Na+
N
a
+
, followed by the formula of a sulfate ion, SO42−
S
O
4
2
−
. Separate the ions with a comma only—spaces are not allowed.
Express your answers as ions separated by a comma.
Answer:
Na⁺,SO₄²⁻
Explanation:
Sodium sulfate is formed by the sodium and sulfate ion.
Sodium is present in group one thus it has only one valence electron. Sodium lose its one valence electron to get complete octet and thus form cation with +1 charge.
On other hand sulfate ion is an anion it carries -2 charge so when it react with sodium there are two sodium atom combine with one sulfate ion inorder to make the compound neutral.
2Na + SO₄²⁻ → Na₂SO₄
Sodium sulfate is actually form when sodium react with sulfuric acid and hydrogen gas is liberated.
Chemical equation:
Na + H₂SO₄ → Na₂SO₄ + H₂
Balance chemical equation:
2Na + H₂SO₄ → Na₂SO₄ + H₂
In a chemical reaction, what happens to the total number of each type of atom?
Answer:
In a chemical reaction the total mass of all the substances taking part in the reaction remains the same. Also, the number of atoms in a reaction remains the same. Mass cannot be created or destroyed in a chemical reaction.
Stoichiometry must be multiplied by the number that is printed on the element's foot in order to determine how many atoms of a certain element there are in a given molecule. Therefore, the quantity of atoms inside a reaction doesn't change.
What is atom?Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms have a central nucleus and electrons that move in a fixed orbit around it. Protons and neutrons are found in the nucleus. Electron has -1 charge while proton has +1 charge.
The combined mass of all of the components involved in a chemical process stays constant. Additionally, the quantity of atoms inside a reaction doesn't change. Chemical reactions cannot produce or destroy mass.
Therefore, the quantity of atoms inside a reaction doesn't change.
To know more about atom, here:
https://brainly.com/question/13518322
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It takes 15.0 seconds to run 100.0 meters if you run .0500 how many meters will you run
Answer:
150 seconds
Explanation:
How many oxygen atoms are in 8.20 g Na 2SO 4?
Answer:
No. of atom =
no.of moles x avagardro's number xatomicity
= weight /molar mass x No x atomicity
=8.2/142 x6.02x10^23 x 4
=0.346 x 10^23(approximately)
Which process squeezes layers of sediment together?
compaction
deposition
erosion
weathering
Answer:
The answer is compaction.
Explanation:
Select the correct responses to the questions from the drop-down menus.
Which type of precipitation freezes when it comes into contact with a cold surface?
Which type of precipitation is round pellets of ice more than 5 millimeters in diameter?
Which type of precipitation is water vapor that condenses into ice crystals in clouds?
Answer:
Which type of precipitation freezes when it comes into contact with a cold surface?
✔ freezing rain
Which type of precipitation is round pellets of ice more than 5 millimeters in diameter?
✔ hail
Which type of precipitation is water vapor that condenses into ice crystals in clouds?
✔ snow
Explanation:
The type of precipitation that freezes when it comes into contact with a cold surface is freezing rain.
The type of precipitation that is round pellets of ice more than 5 millimeters in diameter is hail.
The type of precipitation where water vapor condenses into ice crystals in clouds is snow.
Freezing rain is the rain that is maintained at a temperature that's below freezing by ambient air mass. It's made entirely of liquid droplets.
Read related link on:
https://brainly.com/question/16381514
Ernest Rutherford and Henry
Moseley used this subatomic
particle to differentiate atoms by
their atomic number.
Answer:
electron
Explanation:
The salt copper(II) sulfate dissolves in water according to the reaction: CuSO4(s) Cu2+(aq) + SO42-(aq) (a) Calculate the standard enthalpy change ΔH° for this reaction, using the following data: CuSO4(s) = -771.4 kJ mol-1 Cu2+(aq) = 64.8 kJ mol-1 SO42-(aq) = -909.3 kJ mol-1 kJ (b) Calculate the temperature reached by the solution formed when 13.0 g of CuSO4 is dissolved in 0.109 L of water at 25.0 °C. Approximate the heat capacity of the solution by the heat capacity of 109 g of pure water (specific heat capacity = 4.18 J g-1 °C-1), ignoring the mass of the salt. °C (c) Heats of reaction find practical application in hot packs or cold packs. Would this dissolution reaction be appropriate for the preparation of a hot pack or a cold pack?
Answer:
(a) [tex]\Delta H=-73.1\frac{kJ}{mol}[/tex]
(b) [tex]T_2=38.1\°C[/tex]
(c) Yes, it is appropriated.
Explanation:
Hello.
(a) In this case, given the formation enthalpies for copper (II) sulfate, copper (II) ion and sulfate ion, we can compute the enthalpy change for such process as follows:
[tex]\Delta H=\Delta H_{Cu^{2+}}+\Delta H_{SO_4^{-2}}-\Delta H_{CuSO_4}\\\\\Delta H=64.8-909.3-(-771.4)\\\\\Delta H=-73.1\frac{kJ}{mol}[/tex]
(b) In this case, since 13.0 g of copper (II) sulfate (molar mass: 159.55 g/mol) we can compute the gained heat by water via:
[tex]Q_{water}=-n_{CuSO_4}\Delta H=-13.0g*\frac{1mol}{159.55g}* -73.1\frac{kJ}{mol}\\ \\Q_{water}=5.96kJ=5960J[/tex]
As the heat lost by the reaction is gained by the water, therefore, the final temperature is:
[tex]Q_{water}=m_{water}Cp_{water}(T_2-T_1)\\\\T_2=T_1+\frac{Q_{water}}{m_{water}Cp_{water}}\\ \\T_2=25.0\°C+\frac{5960J}{0.109L*\frac{1000g}{1L}*4.18\frac{J}{g\°C} } \\\\T_2=38.1\°C[/tex]
(c) In this case, since this dissolution reaction is exothermic as it increases the temperature when undergone, we can infer that yes, this dissolution would be appropriate for the preparation of a hot pack, because a cold pack would be with an endothermic dissolution reaction.
Best regards.
* 20 POINTS
A ________ is made of two or more elements chemically combined.
a.
alloy
b.
mixture
c.
element
d.
compound
Answer:
Compound is the answer
what is the formula for sodium hydrogen phosphate
Answer: Na2HPO4
Explanation: this is the formula
Answer:
Na3PO4
Explanation:.
HELP ASAP!!!........
Based on what you observed on the link above,
describe how ice in a teapot is turned into steam.
Liquid
lid
Answer: the particles in the water heats up and the hotter to gets the faster it moves. When there is no where for the heat to go it builds up and pushes its way out and turns to steam when it hits cool air
Explanation:
Using Beer's Law determine the concentration of a dye dissolved in water that has an absorptivity of 1 x 102 cm-1M-1 and produces an absorbance reading 1.0. The length of the cuvette is 1 cm.
Answer:
1 × 10⁻² M
Explanation:
Step 1: Given data
Absorptivity of a dye (ε): 1 × 10² cm⁻¹M⁻¹
Absorbance (A): 1.0
Length of the cuvette (l): 1 cm
Concentration of a dye (C): ?
Step 2: Calculate the concentration of the dye
We will use Beer's Law.
A = ε × l × C
C = A / ε × l
C = 1.0 / 1 × 10² cm⁻¹M⁻¹ × 1 cm
C = 1 × 10⁻² M
The concentration of the dye is 1 × 10⁻² M.
Some dog foods contains corn and wheat that provide the dog with carbohydrates. Which claim explains why carbohydrates are important to cell processes?
A) They are a source of energy.
B) They make amino acids.
C) They form cell membranes.
D) They help chemical processes happen.
(Science 7th grade)
Hello!
The answer is that they are a source of energy!
Hope this helps!
how many seconds are in 1 year
You were tasked to check if the liquid sample you have is a substance or a
mixture. Which among these tests is the BEST way to do so?l.color comparizon
lltaste comparizon
III. Boiling Test
IV. Melting Test
a.I, II, III and IV. b.l,II, and III only
c. I and Ill only
d. I, II, and IV only
Answer:
The correct answer is - option C. I and Ill only.
Explanation:
One never tastes a unknown chemical in chemistry lab especialy a liquid that can be hazardous. Melting test is for solid as a solution is already a liquid state so melting test can not be perform on it.
The two test can be perform on given sample that are color comparison and boiling test to check if it is substance or a mixture. A misture is prepared from mixing different kind of compounds that can give different kind of color while a particular substance give a uniform color always or remain colorless.
Boiling test can be helpful in distinguish a mixture from a substance as a particular sybstance always give a particular boiling point but mixture can be varry and depend of the coponents mixed together
