1. Use Dot and cross method to show the bonding of the atoms and state the number of atoms of each element present
a. Magnesium and Fluorine
b. Sodium and Fluorine
c. Sodium and Oxygen
d. Aluminum and Iodine
2. Write the chemical formula using the 4-step method for:
a) Magnesium sulphide,
b) Magnesium Fluoride,
c) Hydrogen Bromide and
d) Iron (III) Oxide.
Answers
Related Questions
When a 16.8 mL sample of a 0.410 M aqueous hydrocyanic acid solution is titrated with a 0.408 M aqueous sodium hydroxide solution, what is the pH after 25.3 mL of sodium hydroxide have been added?
pH =
Answers
From the calculations and results obtained, the pH of the solution is 12.85. This implies that the solution is basic or we can say it is alkaline.
What is pH?pH is a scale that shows the acidity or alkalinity of a solution.
Number of moles of hydrogen cyanide = 0.410 M * 16.8 /1000 L = 0.0069 moles
Number of moles of NaOH = 0.408 M * 25.3/1000 L = 0.01 moles
Since the reaction is 1:1, hydrogen cyanide is the limiting reactant.
Number of moles of NaOH left over = 0.01 moles - 0.0069 moles
= 0.0031 moles
Total volume = 16.8 mL + 25.3 mL = 42.1 mL or 0.042 L
Molarity of left over hydroxide ions = 0.0031 moles /0.042 L
= 0.07 M
pOH = - log(0.07 M) = 1.15
pH = 14 - 1.15 = 12.85
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Which statement identifies an accurate relationship between metals and nonmetals in the same period of the Periodic Table?
A
Metals generally have higher electronegativity than nonmetals in the same period.
B
Nonmetals generally have a lower, first-ionization energy than metals in the same period.
с
Metals generally have smaller radii than nonmetals in the same period.
D
Nonmetals generally have a higher electronegativity than metals in the same period.
Answers
Answer:
D.) Nonmetals generally have a higher electronegativity than metals in the same period.
Explanation:
A.) is incorrect because within the same period, nonmetals have the higher electronegativity values.
B.) is incorrect because ionization energy usually increases as one goes across the periodic table, meaning metals will generally have lower, first-ionization energies. This is because the protons in the atoms increase as you travel across the periodic table while the outer shell continues to occupy the same energy level. The more protons there are, the greater the attraction between the electrons and protons, making it more difficult to ionize the atom.
C.) is incorrect because within the same period, nonmetals will have the smaller radii. This is because as you go across a period, the protons in the atom increase. The more protons there are, the greater the pull they will have on their electrons. This shrinks the size of the atom.
D.) is correct because as you go across a period, the electronegativity increases. These atoms are more likely to attract electrons due to their higher proton count while simultaneously being a smaller size.
Order these elements from LEAST to GREATEST atomic mass.
A) Li, He N.S
B) He, Li, N, S
C) N, He, Li, s
D) S, N, Li, Hs
Answers
Answer:
B) He, Li, N, S
Explanation:
mass of helium < mass of lithium < mass of nitrogen < mass of sulfur
C. At an old gas station, gasoline leaks from an underground storage tank.
Classification:
Explanation:
Answers
To pevent gasoline leaks, regular maintenance checks and replacement of damaged underground tanks is required.
What causes gasoline leak?Gasoline leaks occurs when tanks are rusty and corroded or where there are loose fitting of pipes and connection points.
Gasoline leak presents a serious environmental hazard as well as threat to life and properties.
Gasoline leaks can cause fire outbreaks which would destroy properties and endanger lives.
Gasoline leaks can also cause land and water pollution killing important aquatic and soil organisms.
Therefore, regular maintenance checks and replacement of damaged underground tanks will prevent gasoline leaks.
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Answer:
To pevent gasoline leaks, regular maintenance checks and replacement of damaged underground tanks is required.
What causes gasoline leak?
Gasoline leaks occurs when tanks are rusty and corroded or where there are loose fitting of pipes and connection points.
Gasoline leak presents a serious environmental hazard as well as threat to life and properties.
Gasoline leaks can cause fire outbreaks which would destroy properties and endanger lives.
Gasoline leaks can also cause land and water pollution killing important aquatic and soil organisms.
Therefore, regular maintenance checks and replacement of damaged underground tanks will prevent gasoline leaks.
Explanation:
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What element is this
Answers
Answer:
the element is lithium answerFe2O3+3H2=2Fe+3H2O
Calculate how many grams of iron can be made from 16.5 grams of Fe2O3 by the equation above.
Answers
Answer:
No of moles of fe2o3 = 16.5/(55.8x2+16x3)=0.103mols
No. Of moles of iron= 0.103 x 2 = 0.206mols
Mass of iron = 0.206 x 55.8 = 11.5g
Explanation:
Sry if I'm wrong
To separate a mixture of p-toluidine and p-nitrotoluene dissolved in ether:
a. extract the ether solution with aqueous HCl and treat the water layer with aqueous NaOH.
b. extract the ether solution with aqueous NaOH and treat the water layer with aqueous HCl.
c. extract the ether solution with water and treat the water layer with aqueous NaOH.
d. extract the ether layer with aqueous HCl and treat the ether layer with aqueous NaOH.
e. extract the ether solution with aqueous HCl and treat the ether layer with aqueous HCl.
Answers
Answer:
extract the ether solution with aqueous HCl and treat the water layer with aqueous NaOH.
Explanation:
p-toluidine is a basic compound, it can react with aqueous HCl to form p-Toluidine hydrochloride and is recovered subsequently.
An alkali such as NaOH can be used to recover the p-toluidine. The neutral compound, p-nitrotoluene, will remain in the ether layer and can be recovered by evaporating the solution.
9. The magnetic pattern of ocean-floor rocks on one side of an ocean ridge is ____. a. a mirror image of that of the other side
b. younger than on the other side
c. much different from the magnetic pattern found in rocks on land d. at right angles to the ocean ridge
Answers
Answer:
is this for quizzes
Explanation:
asdfghkl, dftyuil, cftyhjm
Answer:
The answer is A Mirror Image Of That Of The Other Side
Does photosynthesis take place in animals, plants, or both animals and plants?
only animals
only plants
both animals and plants
Answers
If the pH of an acid rain storm is approximately 3.0, how many times greater is the [H ] in the rain than in a cup of coffee having a pH of 5.0
Answers
Taking into account the definition of pH, the [H⁺] in the rain is 100 times greater than in a cup of coffee.
Definition of pHpH is the Hydrogen Potential. It is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
Mathematically, pH is calculated as the negative base 10 logarithm of the activity of hydrogen ions:
pH= - log [H⁺]
The numerical scale that measures the pH of substances includes the numbers from 0 to 14. The pH value 7 corresponds to neutral substances. Acidic substances are those with a pH lower than 7, while basic substances have a pH higher than 7.
Comparison of [H⁺]In this case, you know:
pH= 3pH= 5You can replace this values in the definition of pH:
3= -log [H⁺] → [H⁺]=1×10⁻³ M5= -log [H⁺] → [H⁺]=1×10⁻⁵ MSolving:
[H⁺]=1×10⁻³ M[H⁺]=1×10⁻⁵ MComparing [H⁺], you get:
[tex]\frac{1x10^{-3} }{1x10^{-5} } =100[/tex]
Finally, the [H⁺] in the rain is 100 times greater than in a cup of coffee.
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Which of the following statements about the density of the blue object is true?
A. The blue object has a density less than 1 g/cm3.
B. The blue object has a density of exactly 1 g/cm3.
C. The blue object has a density greater than 1 g/cm3.
D. None of the conclusions above is certain.
Answers
Answer:
the answer is A it just told me
Explanation:
the quiz told me the correct answer
What is saturation
Give two examples each of acid and basic salt
Answers
Answer:
saturated refers to a point of maximum concentration, in which no more solute may be dissolved in a solvent.
Acid:sulfuric,nitric
Basic salt:Calcium carbonate (CaCO3)
Sodium acetate (NaOOCCH3)
Explanation:
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If 0.200 mol of copper(II) sulfate is dissolved in 275 g of H2O, what is the percent by weight of the copper(II) sulfate in the solution
Answers
Answer:
I think its 0.200x159.6=31.92 if this is correct can u mark me brainliest
The correct formula for the ionic compound formed between Ca and I is CaI
True or False
Answers
The statement "correct formula for the ionic compound formed between Ca and I is CaI" is false.
What is chemical formula?Chemical formula is using of the elements and number to write a compound or element using the chemical terms. The chemical formula re the short form of the name of the elements and compounds.
The chemical formulas or equation are written by using the balanced form of equation by using the number of moles and charge on the elements.
Ca and I are the chemical element of the periodic table, and they combine and written as calcium iodide, CaI₂, because they are ionic compound and iodine contain charge of two. Ionic compounds are the compounds that are formed when they lose to gain electrons to form a bond.
Thus, the statement is false.
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A chemist has a 0.200 M solution of potassium hydroxide (molar mass = 56.1g/mol). What mass of KOH is dissolved in 3.20 L of the solution?
Answers
Answer:
35.904g
Explanation:
[tex]concentration = \frac{mole}{volume} \\ 0.200 = \frac{n}{3.20} \\ n = 0.640mol \\ n \frac{mass}{molar \: mass} \\ mass = n \times molar \: mass \\ molar \: mass = 56.1gmol {}^{ - 1} \\ mass = 56.1 \times 0.640 \\ mass = 35.904g[/tex]
What does the 2 in 2 CO represent?
Answers
Answer:
CO2 is the chemical formula for the compound carbon dioxide. C is the symbol for the element carbon, and O is the symbol for oxygen.
Explanation:
Carbon Dioxide has One Carbon and Two Oxygens.
A calorimeter contains 31.0 mL of water at 13.5 ∘C . When 2.30 g of X (a substance with a molar mass of 76.0 g/mol ) is added, it dissolves via the reaction X(s)+H2O(l)→X(aq) and the temperature of the solution increases to 29.5 ∘C . Calculate the enthalpy change, ΔH, for this reaction per mole of X. Assume that the specific heat of the resulting solution is equal to that of water [4.18 J/(g⋅∘C)], that density of water is 1.00 g/mL, and that no heat is lost to the calorimeter itself, nor to the surroundings. Express the change in enthalpy in kilojoules per mole to three significant figures.
Answers
Answer:
-73.6kJ/mol
Explanation:
The solution is increasing its temperature from 13.5°C to 29.5°C, that means the enthalpy change is < 0
The released heat is determined using the calorimeter equation:
Q = -C×m×ΔT
Where Q is heat,
C is specific heat of the solution (4.18J/g°C)
m is mass of the solution (31.0mL = 31.0g + 2.30g = 33.3g)
And ΔT is change in temperature (29.5°C - 13.5°C = 16°C)
Replacing:
Q = -4.18J/g°C×33.3g×16°C
Q = -2227J are released
This heat is released when 2.30g are dissolved, that is:
-2227J / 2.30g × (76.0g / mol) = -73591J/mol =
-73.6kJ/molDuring the course of a titration experiment, you notice that no matter how much base you add to the sample of acid, the color of the solution does not change. In fact, you have added three times the amount of base you expected to add! What is the next thing you should do to troubleshoot this problem
Answers
Answer:
Add a few drops of indicator to your flask. Perhaps you forgot to add them.
Explanation:
The next thing you should do to troubleshoot this problem is to add an indicator which is responsible for color change.
What is an indicator?
Indicator is defined as a chemical substance which is chemically a weak acid or a weak base which changes it's color depending upon the concentration of hydrogen ions present in the solution.They dissociate slightly in water to produce ions.
These are generally derived from plant pigments and are of slightly acidic or basic in nature.There are three types of indicators:
1) natural indicators
2) synthetic indicators
3) olfactory indicators.
These are mainly used in determination of end point of titrations. Every indicator has it's pH range in which it can perform effectively.These are usually organic compounds.
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Please hurry!!! True or false? In a chemical reaction, energy may be gained or lost but the atoms stay the same
Answers
Answer:
it is actually false
Explanation:
You received an unsolicited proposal from a self-declared inventor who is seeking investors for the development of his latest idea: a device that uses heat extracted from the ground by a heat pump to boil water into steam that is used to heat a home and to power a steam engine that drives the heat pump. This procedure is potentially very lucrative because, after an initial extraction of energy from the groin, no fossil fuels would be required to keep the device running indefinitely. Would you invest in this idea? State your conclusion clearly and present detailed arguments to support it.
Answers
Answer: Yes
Explanation:
Yes, i would invest in this idea, Because the procedure looks very lucrative. Because the initial extraction of the energy from the ground requires no fossil fuel to keep the device running or in operation, rather the heat extracted would be used to heat a heat pump which would boil into steam and in turn used to drive a or power a steam engine.
Ionic compounds form
crystal structures.
molecular structures.
pure elements.
neutral elements.
Answers
Answer:
A, crystal structures.
Explanation:
Answer:
A
Explanation:
What is the main molecule that provides the energy to produce ATP?
Answers
Answer: glucose
Explanation:
Need help ASAP!! ->> Neon occurs naturally as the isotopes Ne-20, Ne-21, and Ne-22. Which isotope is most abundant? Why do you say this?
Please answer in sentences thank you!
Answers
Answer:
Neon-20 would be the most abundant isotope among the three.
Explanation:
The relative atomic mass of an element is the average of the relative isotope mass of its naturally-occurring isotopes, weighted according to the relative abundance of each isotope.
The relative isotope mass of an isotope atom is approximately the same as its mass number. The relative isotope mass of one neon-20 atom is approximately [tex]20[/tex]. Similarly, the relative isotope mass of one neon-21 atom and one neon-22 atom will be [tex]21[/tex] and [tex]22[/tex], respectively.
The relative atomic mass of neon is approximately [tex]20.180[/tex] (as seen on a modern periodic table.) This number is supposed to be the weighted average of the relative isotope mass of neon-20, neon-21, and neon-22 according to their relative abundance.
If the three isotopes were to have a relatively equal abundance, then the relative atomic mass of neon should be very close to [tex]21[/tex]. However, that's not actually the case. The commonly-accepted relative atomic mass of neon, [tex]20.180[/tex], is significantly tilted towards [tex]20[/tex], which is the (approximate) relative isotope mass of neon-20.
The question assumes that neon-20, neon-21, and neon-22 are the only three naturally-occurring isotopes of neon. In other words, there's no naturally-occuring isotope of neon with an isotope mass smaller than that of neon-20. Based on that assumption, neon-20 must have been considerably more abundant than the heavier neon-21 and neon-22 to ensure that weighted average [tex]20.180[/tex] is much smaller than the relative isotope mass of neon-21 and neon-22.
PLEASE HELLLLOOPLPPPPP
Answers
Answer:
the answer is d.Class there u go i hope its riht
In Earth’s mantle there are convection currents. The convection currents flow in a _________ shape. As the hot magma ________________, the colder magma ___________________. These convection currents are a continuous_______________. This means that convection currents will _____________ stop because they have a constant source of heat energy. Convection currents move the lithosphere and cause many events on the surface including_____________ and _____________.
Words:
rises
eventually
system
earthquakes
triangular
circular
tornadoes
volcanoes
never
sinks
Answers
Answer:
4
5
2
6
3
1
6
7
.......
.
.
.
.
.
..
A scientist performed four investigations using eight different liquids. In each investigation, the scientist combined two of the liquids under a fume hood and recorded observations in the table below.
Scientist’s Observations
Investigation
Observations After Two Liquids Are Combined
1
The temperature of the combined liquids increased, and a solid substance formed.
2
The temperature of the combined liquids decreased, and bubbles formed.
3
One liquid settled to the bottom of the beaker, and the other liquid rose to the top.
4
The combined liquids turned from clear to a bright purple.
In which investigation is it likely that the liquids reacted chemically?
Substance 1
Substance 2
Substance 3
Substance 4.
Answers
Chemical reactions are indeed an essential aspect of technology, society, and life itself. Therefore, in Substance 2 investigation, liquids reacted chemically.
What is Chemical reaction?A chemical reaction is a process that converts one or more compounds, known as reactants, into one or more distinct substances, known as products. Chemical elements and compounds are examples of substances. A chemical reaction reconfigures the component atoms of the reagents to produce various products.
Chemical reactions are indeed an essential aspect of technology, society, and life itself. Many activities involving oxidation processes that have recognized and practiced for hundreds of years include burning fuels, melting iron, creating glass or pottery, brewing beer, including making wine and cheese. In Substance 2 investigation, liquids reacted chemically.
Therefore, in Substance 2 investigation, liquids reacted chemically.
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A mixture contains NaHCO3 together with unreactive components. A 1.75 g sample of the mixture reacts with HA to produce 0.561 g of CO2. What is the percent by mass of NaHCO3 in the original mixture?
Answers
Answer:
[tex]\%NaHCO_3=61.2\%[/tex]
Explanation:
Hello.
In this case, since the reaction between sodium bicarbonate and a symbolic HA is:
[tex]NaHCO_3+HA\rightarrow NaOH+CO_2[/tex]
For 0.561 g of carbon dioxide (molar mass = 44 g/mol) we can compute the required mass of sodium bicarbonate (molar mass = 84 g/mol ) via stoichiometry:
[tex]m_{NaHCO_3}=0.561gCO_2*\frac{1molCO_2}{44gCO_2}*\frac{1molNaHCO_3}{1molCO_2}* \frac{84gNaHCO_3}{1molNaHCO_3}\\ \\m_{NaHCO_3}=1.071gNaHCO_3[/tex]
Then, the percent by mass of sodium bicarbonate in the original mixture is obtained by dividing the mass of the sodium bicarbonate from which the CO2 was yielded by the total mass of the mixture:
[tex]\%NaHCO_3=\frac{1.071g}{1.75g}*100\%\\ \\\%NaHCO_3=61.2\%[/tex]
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As you move down the periodic table atoms get bigger. This is because ____________.
Answers
Answer:
Because the atoms have more energy levels
Explanation:
Hope this helps:)....if not sorry for wasting your time and may God bless you:)
separate the precipitate formed when aqueous silver nitrate is added to
aqueous sodium chloride.
Answers
This reaction produces a white precipitate. It is silver chloride:
[tex]AgNO_{3} + NaCl[/tex] → [tex]AgCl[/tex]↓ [tex]+[/tex] [tex]Na^{+} + NO^{-} _{3}[/tex]
Choose 2 of the above examples and explain why you chose chemical or
physical. Please choose one of each type of change. Back up your explanation.
Answers
Answer:
PHYSICAL:
An example of a physical change would be clay, for instance, you take out clay you then sculpt it into a spere, this is a physical change.
CHEMICAL
An example of a chemical change is when you take vinegar then put baking soda in it, it has a chemical reaction
hope this helped <3