Answer: in order of increasing atomic number.
Explanation: Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.
Answer:
What pattern do you see?
Chemical families have the same number of valence electrons.
Make a rule: Based on your data, how are elements arranged into chemical families?
They are arranged vertically depending on how many valence electrons they have, if they have the same amount, they will have the same chemical family in each column.
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314 gmol, 40.165 gmol, and 40.554 gmol. If the accepted value for the molar mass is 40.304 gmol, what is the percent relative error for the average of this data?
Answer:
Percent relative error = 0.191%
Explanation:
Relative error is a measure of accuracy (How closeness is the measure to the accepted value) for a determined data. The formula is:
Percent relative error = |Experimental - Accepted| / Accepted * 100
Where experimental is the average of the data:
(40.220g/mol + 40.654g/mol + 40.314g/mol + 40.165g/mol + 40.554g/mol) / 5 =
40.381g/mol
Replacing using accepted value = 40.304g/mol:
|40.381g/mol - 40.304g/mol| / 40.304g/mol * 100
Percent relative error = 0.191%A sample of saturated clay was placed in a container and weighed. The weight was 6N. The clay in its container was placed in an oven for 24 hours at 105° C. The weight reduced to a constant value of 5N. The weight of the container is 1N. If G-2.7, determine the:
(a) water content;
(b) void ratio;
(c) bulk unit weight;
(d) dry unit weight;
(e) effective unit weight.
Answer is given below
Explanation:
given data
weight = 6N
temp = 105° C
weight reduced = 5N
solution
weight of container is 1N
SO W = (6-1) = 5
And Wd = 5 - 1 = 4
so
moisture content is
moisture content = [tex]\frac{W-Wd}{Wd} \times 100[/tex] .......1
moisture content = [tex]\frac{5-4}{4} \times 100[/tex]
moisture content = 25%
and
as we know density of soil soild = 2700 kg/m³
density of water = 1000 kg/m³
and sp gravity of soil = [tex]\frac{2700}{1000}[/tex] = 2.7
so
now we get here bulk unit weight
bulk unit wt = [tex]Yw \times [\frac{G+e}{1+e}][/tex] ..........2
bulk unit wt = [tex]9.01 \times [\frac{2.7 + 0.675}{1+0.675}][/tex]
bulk unit wt = 19.766 KN/m³
and
so dry unit wt will be
dry unit wt = [tex]\frac{Ysat}{1+w}[/tex] ..............3
dry unit wt = [tex]\frac{19.766}{1+0.25}[/tex]
dry unit wt = 15.813 kN/m³
why do we need nucleic acid in our cells?
Explanation:
Nucleic acids are the most important macromolecules for the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.
Last week at a tax free sale, Ms. Kuhn bought 4 shirts for $15.95 each and 2 new belts
that cost $8.95 each. If she paid with a $100 bill, how much change did she receive?
$18.30
$75.10
$2490
$24.90
Answer:
$18.30
Explanation:
The change is the amount left over after the selling price has been matched by the buyer.
Let us find the total cost of what of Ms. Kuhn bought;
For the shirt;
Cost = 4 shirts for $15.95 each = 4(15.95) = $63.8
2 new belts for $8.95 each = 2(8.95) = $17.9
Total cost = $63.8 + $17.9 = $81.7
The amount of change left = $100 - $81.7 = $18.3
Which of the following is the set of conditions under which a material becomes a supercritical fluid?
A. real gas point
B. critical point
C. extreme point
D. triple point
(multiple choice)
which of the following is the best thermal insulator?
1. Steel
2. Iron
3. Polystyrene
Answer:
3
Explanation:
Answer:
best guess is polystyrene
Explanation:
first answer will get brainliest
Answer:
Incorrect
Explanation:
Mole ratios are derived from the coefficients in front of the number, N2O does not have a 2 in front of it, the real mole ratio would be 4/1
Answer:
Correct
Explanation:
I had the same problem and I put correct, and it was correct.
Which of the following is the Arrhenius equation?
Answer:
A is the answer the reason why is because I got it right when I was doing my test
which would be a stronger acid H3PO4 or H3PO2
Answer:
h3po2
Explanation:
Answer:
i think it is H3PO4
Explanation:
Halogenated compounds are particularly easy to identify by their mass spectra because chlorine and bromine occur naturally as mixtures of two abundant isotopes. Chlorine occurs as 35Cl (75.8%) and 37Cl (24.2%); Bromine occurs as 79Br (50.7%) and 81Br (49.3%); Boron compounds also stand out owing to the two isotopes 10B (19.9%) and 11B (80.1%).
Required:
a. At what masses do the molecular ions occur for the following formulas?
b. What are the relative percentages of each molecular ion?
Answer:
Explanation:
From the given information:
The compound in question here is [tex]\mathbf{C_2H_5Br}[/tex]
The molar mass of [tex]\mathbf{C_2H_5Br}[/tex] with 79 Br is;
= (2 × 12) + (1 × 5) + 79
= 108 g/mol
The molar mass of [tex]\mathbf{C_2H_5Br}[/tex] with 81 Br is:
= (2 × 12) + (1 × 5) + 81
= 110 g/mol
Thus, the mass at which the molecular ions occurs are:
108 and 110.
The relative percentage of mass 108 occurred at 50.7%
The relative percentage of mass 110 occurred at 49.3%
What is the difference between the grassland and savanna biomes?
A)Grassland biomes are closer to the equator and receive more rain.
B)Savanna biomes are closer to the equator and receive more rain.
C)Grassland biomes contain mostly grasses.
D)Savanna biomes contain mostly grasses.
Answer:
C)Grassland biomes contain mostly grasses.
Explanation:
The main differences between a savanna biome and a grassland is that grasslands biomes contain mostly grasses.
Savanna are made up of both grasses and shrubs.
Savanna are a mix of grasslands with some scattered trees in the area. Grasslands are open grass fields. They do not contain much trees as such. The savanna and grasslands are renowned for their fauna diversity of beasts.A 1.018 g sample pure platinum metal was reacted with HCl to form 1.778 g of a compound containing only platinum and chlorine. What is the percent by mass of platinum?
Answer:
57.26 %
Explanation:
Step 1: Write the balanced equation
Pt + 2 HCl ⇒ PtCl₂ + H₂
Step 2: Calculate the mass of Pt in 1.778 g of PtCl₂
According to the law of conservation of the mass, all the mass of Pt in the reactants must be present in the products. Since PtCl₂ is the only product that contains Pt, the mass of Pt is 1.018 g
Step 3: Calculate the percent by mass of platinum in PtCl₂
We will use the following expression.
%Pt = mPt / mPtCl₂ × 100%
%Pt = 1.018 g / 1.778 g × 100% = 57.26 %
Select the correct coefficients to balance the reaction given below.
__Al + ___O₂ → ____ Al₂ O₃
Answer:
4Al+3O2→2Al2O3
Explanation:
which type of bond involves 2 different metals?
A. ionic
B. Covalent
C.Metallic
D. Bonding would not occur
Answer:
iconic bond is the answer
I hope it helps you ✌
A 1.018 g sample pure platinum metal was reacted with HCl to form 1.778 g of a compound containing only platinum and chlorine. Determine the empirical formula of this "Pt-Cl" Compound.
Answer:
[tex]PtCl_4[/tex]
Explanation:
Hello!
In this case, since HCl and Pt react according to the following chemical equation:
[tex]HCl+Pt\rightarrow PtCl_x+H_2[/tex]
Whereas PtClx is the compound containing Pt and Cl; thus, since 1.018 g out of 1.778 g correspond to Pt and therefore 0.760 g to chlorine, so we determine the empirical formula of this compound by firstly computing the moles of each element:
[tex]n_{Pt}=1.018gPt*\frac{1molPt}{195.084gPt}=0.00522molPt\\\\\\n_{Cl}=0.760gCl*\frac{1molCl}{35.45gCl} =0.0214molCl[/tex]
Now, we divide the each moles by those of Pt as the fewest ones in order to compute their subscripts in the empirical formula:
[tex]Pt=\frac{0.00522}{0.00522}=1 \\\\Cl=\frac{0.0214}{0.00522} =4[/tex]
Thus, the required formula is:
[tex]PtCl_4[/tex]
Best regards!
Which element is classified as a transition metal?
A) lithium (Li)
B) zirconium (Zr)
C) tellurium (Te)
D) xenon (Xe)
Answer:
C) tellurium (Te) is the correct answer.
Choose the catabolic reaction.
A. Breaking down a complex molecule
B. Synthesizing a complex molecule
C. CO2 and H2O combining to form carbonic acid.
Answer:
B. Synthesizing a complex molecule
Explanation:
Hello!
In this case, since catabolic reactions are related to the synthesis of complex biomolecules and metabolic reactions to the breaking down of complex molecules to obtain energy from (say start), we infer that the appropriate answer is:
B. Synthesizing a complex molecule
Because regardless C. also mentions the synthesis of a compound, carbonic acid is not a complex one in comparison to the biomolecules we produce during our cellular cycles.
Best regards!
A geochemist in the field takes a 36.0 mL sample of water from a rock pool lined with crystals of a certain mineral compound X. He notes the temperature of the pool, 170 C, and caps the sample carefully. Back in the lab, the geochemist filters the sample and then evaporates all the water under vacuum. Crystals of are left behind. The researcher washes, dries and weighs the crystals. They weigh 3.96 g. Using only the information above, can you calculate the solubility of X in water at 17.0C? If you said yes, calculate it.
Answer:
Yes, 0.11g/mL is the solubility of X in water at 17.0°C.
Explanation:
As the sample of water has crystals around it, the solution is oversaturated at 17.0°C. The water contains the maximum amount of X at 17.0°C, this concentration is called solubility. Thus, yes, we can calculate solubility in water at 17.0°C
The concentration of the crystals is 3.96g in 36.0mL, that is:
3.96g / 36.0mL =
0.11g/mL is the solubility of X in water at 17.0°CPLZ HELP ASAP WILL
GIVE BRAINLISTS TO RIGHT ANSWER
2KCIO3 → 2KCI + 302
How many grams of potassium chloride are produced if 52 g of potassium chlorate decompose?
A )32 g KCI
B )19 g KCI
C)44 g KCI
D)1.5 g KCI
Answer:
A) Mass = 32 g of KCl
Explanation:
Given data:
Mass of potassium chloride produced = ?
Mass of potassium chlorate = 52 g
Solution:
Chemical equation:
2KClO₃ → 2KCl + 3O₂
Number of moles of KClO₃:
Number of moles = mass/molar mass
Number of moles = 52 g/ 122.55 g/mol
Number of moles = 0.424 mol
Now we will compare the moles of KClO₃ and KCl
KClO₃ : KCl
2 : 2
0.424 : 0.424
Mass of KCl:
Mass = number of moles × molar mass
Mass = 0.424 mol × 74.55 g/mol
Mass = 32 g
If you rewite the following word equation as a balanced chemical equation, what will the coefficient and symbol for iodine be?
bromine + potassium iodide → potassium bromide + iodine
A 2I
B I
C 2I
D I2
E 2I2
The coefficient and symbol for iodine be I₂.
What is the coefficient in a chemical equation?Coefficients are the numbers used to balance chemical equations and are placed in front of a chemical symbol or formula. It tells us about how many atoms or molecules of substance or compound are involved in the reaction.As in mathematics, coefficient is the number used in front of a variable similarly in chemistry, coefficient is a number used in chemical equation, just as a prefix of chemical formula to define the number of molecules reacting and producing in a reaction. We add coefficients to balance the chemical equations so as to assure that law of conservation of mass is being followed.bromine + potassium iodide → potassium bromide + iodine
The balanced chemical equations:
Br₂ + 2KI → 2KBr + I₂
2KBr means 2 molecules of potassium iodide.
From the above balanced equation, we know that the coefficient of bromine = 2, iodine = 2, potassium iodide = 2and potassium bromide = 2.
Hence, option D is the correct answer.
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a titanium bicycle frame displays 0.250 L of water and has a mass of 1.21kg. what is the density of the titanium on g/cm3?
Answer:
$4.49 g/cm3
Explanation:
Density=Mass/Volume
plzz put brainiest
Liquid hexane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 64. g of hexane is mixed with 72.0 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.
Answer:
45.7g of CO₂ is the maximum amount of carbon dioxide that could be produced.
Explanation:
Hexane, C₆H₁₄, reacts with O₂ to produce H₂O and CO₂ as follows:
C₆H₁₄ + 13/2O₂ → 7H₂O + 3CO₂
Where 1 mole of hexane reacts with 13/2 moles of O₂.
To solve this question we need to convert the mass of each reactant to moles in order to find the limiting reactant. With limiting reactant we can find the maximum amount of CO₂ produced:
Moles C₆H₁₄ -Molar mass: 86.18g/mol-:
64g C₆H₁₄ * (1mol / 86.18g) = 0.7426 moles C₆H₁₄
Moles O₂ -Molar mass: 32g/mol-:
72.0g O₂ * (1mol / 32g) = 2.25 moles O₂
For a complete reaction of 2.25 moles of O₂ are required:
2.25 moles O₂ * (1mol C₆H₁₄ / 13/2 moles O₂) = 0.346 moles of C₆H₁₄
As there are 0.7426 moles of C₆H₁₄, C₆H₁₄ is the excess reactant and:
Oxygen is limiting reactant.
The maximum moles of CO₂ that could be produced are:
2.25 moles O₂ * (3mol CO₂ / 13/2 moles O₂) = 1.038 moles CO₂
In grams:
1.038 moles CO₂ * (44.01g / mol) =
45.7g of CO₂ is the maximum amount of carbon dioxide that could be produced.A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain
Answer:
d. 10 million years
Explanation:
These are the options for the question
Choose one answer.
a. 2.5 million years
b. 5 million years
c. 15 million years
d. 10 million years
✓half-life of the radioactive substance= 5 million years
✓ Then for every 5 million years, original radioactive given (100%) percentage is reduced by factor of 1/2.
✓ 1st 5 million year; After the first 5 million years, the original radioactive is reduced as;
(100%) × 1/2 = 50% remains
✓2nd 5 million year: At 10 millions year, the 50% remaining radioactive is reduced by factor of 1/2
(50%) × 1/2 = 25% remains
Hence, at At 10 millions years 25% of the original radioactive atoms remain
.
Answer:
10 million years
Photosynthesizing organisms use ____
to produce glucose.
Answer: Photosynthesizing organisms use carbon dioxide and water to produce glucose.
Explanation:
Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
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.
[tex]6CO_2+6H_2O\overset{sunlight}\rightarrow C_6H_{12}O_6+6O_2[/tex]
In chemical reactions, elements tend to combine with other elements to____ stability and ____ total energy
Answer:
In chemical reactions, elements tend to combine with other elements to INCREASE_ stability and DECREASE total energy.
Explanation:
The chemical compounds when joining are more stable in external media such as solvents or solutions already formed, although this union with another chemical compound removes total energy from the compound.
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?
Answer:
56 J
Explanation:
Step 1: Given data
Force applied on the object (F): 7 NDisplacement of the object (d): 8 mStep 2: Calculate the work (w) done on the object
We can find the work done on the object using the following expression.
w = F × d × cosθ
where
θ is the angle between F and d
Since F and d occur in the same direction, θ = 0° and cosθ = 1. Then,
w = F × d × 1
w = F × d
w = 7 N × 8 m = 56 J
S2- has the same electron configuration as which neutral element?
Answer:
ANSWER OS HERE
Explanation:
THE O2- has two more extra electrons due to presence of 2 negative charges so a total of 10 electrons and the element that has 10 electrons in the periodic table in its neutral state is Neon (Ne) ( atomic number (10) = no.of protons = no. of electrons) so neutral element with same electron configuration as O2- is Ne. Log in or register to post comments.
The electron configuration of the neutral atom is an useful place to start when trying to determine the electron configuration of an ion.
What is the idea behind this?The neutral atom in your situation is sulfur (S), which is found in group 16 of period 3 of the periodic chart. A neutral sulfur atom has a total of 16 electrons surrounding its nucleus since sulfur has an atomic number of 16. Thus, a neutral sulfur atom will have the following electron configuration. Now, a neutral sulfur atom receives two more electrons to create the sulfide anion, or S2. These two electrons will be added to the 3p-orbitals, which can hold a maximum of two protons, as you can see in the configuration of the neutral atom. between them, a maximum of six electrons. Thus, the sulfide anion's electron configuration will be the electron configuration of neon, the noble gas that appears before sulfur in the periodic table, will be used in the shorthand notation for noble gases for the sulfide anion.
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7. Use the concepts of relative abundance and relative weight to explain why carbon has an atomic mass of 12.011 amu when there are three isotopes of carbon weighing 12 amu, 13 amu and 14 amu. Why is the atomic mass not 13?
The uncertainties of the delta measurements and the uncertainty of the atomic weight derivedfrom the best measurement of isotopic abundances constrain the number of significant figures in theatomic-weight values of the upper and lower bounds. For carbon, the fifth digit after the decimal pointis uncertain because of the uncertainty value of 0.000 027. Therefore, the number of significant digitsin the atomic-weight value is reduced to four figures after the decimal point. The Commission may rec-ommend additional conservatism and reduce the number of significant figures further. For the lowerbound of carbon, 12.009 635 is truncated to 12.0096. For an upper bound, the trailing digit is increasedto ensure the atomic-weight interval encompasses the atomic-weight values of all normal materials. Inthe case of carbon, the upper bound is adjusted from 12.011 532 to 12.0116 to express four digits afterthe decimal point. The lower and upper bounds are evaluated so that the number of significant digits ineach is identical. If a value ends with a zero, it may need to be included in the value to express therequired number of digits. The following are examples of lower and upper atomic-weight bounds foroxygen that could be published by the Commission in its various tables.
---------------------------
Extracted from" Atomic weights of the elements 2009 (IUPAC Technical Report)"
Calculate the molarity (M) if 3.35g of H3PO4 is dissolved in water to give a total volume of 200mL
Answer:
0.171 M
Explanation:
Step 1: Given data
Mass of H₃PO₄ (solute): 3.35 gVolume of solution (V): 200 mLStep 2: Calculate the moles of solute
The molar mass of H₃PO₄ is 97.99 g/mol.
3.35 g × 1 mol/97.99 g = 0.0342 mol
Step 3: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
200 mL × 1 L/1000 mL = 0.200 L
Step 4: Calculate the molarity of the solution
We will use the definition of molarity.
M = moles of solute / liters of solution
M = 0.0342 mol/0.200 L = 0.171 M
us
If the mole fraction of NaCl in an
aqueous solution is 0.0927, what is
the weight/weight % (percent by
mass) of NaCl.
Molar Mass
Naci: 58.44 g/mol
H2O: 18.016 g/mol
Answer:
24.9%
Explanation:
According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:
0.0927 × 100 = 9.27%
Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;
100% - 9.27% = 90.73%
THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles
N.B: mole = mass/molar mass
Given the Molar Mass
NaCl: 58.44 g/mol
H2O: 18.016 g/mol
For NaCl;
0.0927 = mass/58.44
mass = 0.0927 × 58.44
5.42g
For H2O;
9.073 = mass/18.016
mass = 9.073 × 18.016
= 16.35g
Total mass of solution = 16.35g + 5.42g = 21.77g
Mass percent of NaCl = mass of NaCl/total mass × 100
% mass of NaCl = 5.42g/21.77g × 100
= 0.249 × 100
= 24.9%
Answer:
24.9
Explanation: