Which statement describes the periodic law?
Help please now!
Answer:
Answer is: elements in the same group have similar chemical properties. Periodic law is the arrangement of the elements in order of increasing atomic number.
How much heat is added if .0948g of water is increased in temperature by .728 degrees C?
.289 J
.803 J
1.46 J
.055 J
Answer:
0.289J of heat are added
Explanation:
We can relate the change in heat of a substance with its increasing in temperature using the equation:
q = m*ΔT*S
Where Q is change in heat
m is mass of substance (In this case, 0.0948g of water)
ΔT = 0.728°C
S is specific heat (For water, 4.184J/g°C)
Replacing:
q = 0.0948g*0.728°C*4.184J/g°C
q = 0.289J of heat are added
please solve this question
Answer:
b) it gets accumulated in the respiratory system which then halts or slows down the supply of oxygen to the brain hence leading to death
which one of the following is not a mixture?Air,mercury ,milk,cement
mercury is not a mixture it is a element
Answer:
mercury
Explanation:
Choose the answer that is not correct: RER is: Group of answer choices The ratio of carbon dioxide produced to oxygen consumed An indication of the percentage of carbohydrate metabolized An indication of the percentage of lipid metabolized An approximation of kilocalories obtained per liter of oxygen consumed An indication of calories consumed during anaerobic energy production
Answer:
An indication of calories consumed during anaerobic energy production
Explanation:
RER stands for respiratory exchange ratio, which is the ratio of the volume of carbon dioxide, CO₂, produced to the volume of oxygen, O₂ used in metabolism. RER is used in determining the respiratory quotient during aerobic exercise and rest, from which it can be determined if carbohydrate or fat is the source of fuel consumed in the production of energy for the body through metabolism
Therefore, the answer that is not correct is an indication of calories consumed during anaerobic energy production
3. Determine the pH value for calcium hydroxide, Ca(OH), with concentration of
0.05 mol dm3. [pH + pOH = 14).
Explanation:
Ca(OH) is a base
pOH = -Log[OH]
[OH] = 0.05
pOH = -Log(0.05)
pOH = 1.3
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 2
pH = 12.7
Which statement best describes what happens as thermal energy from the
sun warms the pavement?
A. The thermal energy absorbed by the pavement is destroyed.
B. The thermal energy that is not absorbed by the pavement is
destroyed.
C. Some thermal energy is absorbed by the pavement, and some is
destroyed.
D. The thermal energy of the sun is transferred to the pavement.
Answer:
D
Explanation:
The correct answer would be that the thermal energy of the sun is transferred to the pavement.
Thermal energy refers to the internal energy possessed by a system by virtue of the movement of molecules within such a system. In other words, it is the heat energy possessed by a system.
When the thermal energy from the sun warms the pavement, it means that the thermal energy from the sun has been successfully transferred to the pavement. Thermal energy can be transferred by conduction, convection, or by radiation depending on whether the system is a solid, liquid, gas respectively.
The correct option is, therefore, D.
How many moles are there in 2.3 x 1024 atoms of
sulfur?
Explanation:
The steps given in the question are incorrect.
Step 1 should be convert atoms to moles (n). Step 2 should be convert moles (n) to mass (m).
Step 1
Use dimensional analysis to convert the number of atoms to moles.
1 mole atoms = 6.022 × 10²³ atoms
n(Ag) = 2.3 × 10²⁴ Ag atoms × (1 mol Ag/6.022 × 10²³ Ag atoms) = 3.8193 mol Ag
Step 2
Convert the moles of Ag to mass.
mass (m) = moles (n) × molar mass (M)
n(Ag) = 3.8193 mol Ag
M(Ag) = atomic weight on the periodic table in g/mol = 107.868 g Ag/mol Ag
m(Ag) = 3.8193 mol × 107.868 g/mol = 412 g Ag = 410 g Ag rounded to two significant figures
The mass of 2.3 × 10²⁴ Ag atoms is approximately 410 g.
Answer:
[tex]\boxed {\boxed {\sf 3.8 \ moles \ of \ sulfur}}[/tex]
Explanation:
We are asked to convert a number of atoms to moles.
We can convert atoms to moles using Avogadro's Number, which is 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are atoms of sulfur. There are 6.022 ×10²³ atoms of sulfur in 1 mole of sulfur.
We use dimensional analysis to convert atoms to moles. This involves setting up ratios. Use Avogadro's Number and the underlined information to make a ratio.
[tex]\frac {6.022 \times 10^{23} \ atoms \ S}{1 \ mol \ S}[/tex]
We are converting 2.3 ×10²⁴ atoms of sulfur to moles, so we multiply by this value.
[tex]2.3 \times 10^{24} \ atoms \ S *\frac {6.022 \times 10^{23} \ atoms \ S}{1 \ mol \ S}[/tex]
Flip the ratio. It is equivalent, but it allows the units of atoms of sulfur to cancel.
[tex]2.3 \times 10^{24} \ atoms \ S *\frac {1 \ mol \ S}{6.022 \times 10^{23} \ atoms \ S}[/tex]
[tex]2.3 \times 10^{24} *\frac {1 \ mol \ S}{6.022 \times 10^{23} }[/tex]
[tex]\frac {2.3 \times 10^{24} }{6.022 \times 10^{23} } \ mol \ S[/tex]
[tex]3.819329127 \ mol \ S[/tex]
The original measurement of atoms (2.3 ×10²⁴) has 2 significant figures, so our answer must have the same. For the number we calculated that is the tenths place. The 1 in the hundredths place to the right (3.819329127) tells us to leave the 8 in the tenths place (3.819329127).
[tex]3.8 \ mol \ S[/tex]
2.3 ×10²⁴ atoms of sulfur is equal to approximately 3.8 moles of sulfur.
A place where animals are protected in their natural habitat is called ------------------
answer is wildlife sanctuary
Answer:
a wildlife sanctuary
Explanation:
What is the pressure in atm exerted by 1.8 g of H2 gas exert in a 4.3 L balloon at 27ºC? R = 0.821(L*atm) / (mol*K)
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The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm
What is Ideal gas law ?The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
Let's convert grams to moles (via molar mass).
Molar Mass (H₂) : 2 (1.008 g/mol)
Molar Mass (H₂) : 2.016 g/mol
1.8 grams H₂ 1 mole
---------------------- x ---------------------- = 0.893 moles H₂
2.016 grams
The Ideal Gas Law equation looks like this:
PV = nRT
In this equation,
P = pressure (atm) V = volume (L) n = moles R = Ideal Gas Constant (0.0821 L*atm/mol*K)T = temperature (K)After converting Celsius to Kelvin, you can put the given values into the equation and simplify to find the pressure.
P = ? atm R = 0.0821 L*atm/mol*K
V = 4.3 L T = 27 °C + 273.15 = 300.15 K
n = 0.893 moles
PV = nRT
P (4.3 L) = (0.893 moles) (0.0821 L*atm/mol*K)( 300.15 K)
P (4.3 L) = 22.0021
P = 5.12 atm
Therefore, The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm
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value of MA is always lesser thàn 1 why?
Answer:
because the load arm is greater than the effort arm. As we know that when the load arm is greater than the effort arm, the mechanical advantage will always be lesser than one, which results in gain in speed
There is 25.3 mL of the sulfuric acid solution; the sulfuric acid concentration is 2.30 M. Your base solution is 1.00 M. What is the volume in mL of base that is required to complete the neutralization of the acid
Answer:
The volume of the base is 0.05819·x L, where x is the number of moles of base that combines with one mole of sulfuric acid
Explanation:
The volume of the sulfuric acid, V = 25.3 mL = 25.3 × 10⁻³ L
The concentration of the sulfuric acid, c = 2.30 M
The concentration of the base, [tex]c_{base}[/tex] = 1.00 M
Let the mole ratio of the acid to base be 1 : x
The number of moles of sulfuric acid present, n = c × V
∴ n = 2.30 M/L × 25.3 × 10⁻³ L = 0.05819 moles
The number of moles of sulfuric acid present, n = 0.05819 moles
1 mole of sulfuric acid combines with x moles of base
Therefore, 0.05819 moles of sulfuric acid will combine with 0.05819·x moles of base
The number of moles of base, [tex]n_{base}[/tex] = 0.05819·x moles
Therefore, the volume of base, [tex]V_{base}[/tex] = [tex]n_{base}[/tex]/[tex]c_{base}[/tex]
∴ [tex]V_{base}[/tex] = 0.05819·x/1 ≈ 0.05819·x L
The volume of base, [tex]V_{base}[/tex] ≈ 0.05819·x L.
plz help me with this one question
I will give u like,rate you 5 star and also follow u back.ppz help me
Answer:
Cl2(g) + H2O <–> HOCl + H+ + Cl-
Chlorine is the most popular way for the sterilization of water.
Cl2 + H2O → HOCl + HCl
what happens to bases when mixed with acids?
They form salt + water.
and the rxn is known as neutralisation rxn
Answer:
When an acid and a base are placed together, they react to neutralize the acid and base properties, producing a salt. Acid-base reactions that do not occur in water usually also produce salts, but they may also produce complex ions.
Helpful Link:
https://sciencing.com/happens-acid-base-combined-5132830.html
cual es la importancia de los solidos en la vida ?
Answer:
La comida es un sólido y no podemos vivir sin comida. Algunos sólidos son buenos conductores de calor y electricidad; otros son aislantes. Los sólidos se utilizan todos los días en la vida.
I have no idea how to do this and need help
Answer:
60.55%
Explanation:
nO3=155/48
nO2 used: 3/2nO3=4.84375
percent yield: 4.84375/8=60.55%
what is the percentage composition of water in crystallization of oxalic acid
Answer:
5.17 percentage is water
Explanation:
answer from gauth math
In an exothermic reaction, heat is
released into the surroundings. How does this affect entropy?
particles in the surroundings move slower and have decreased entropy.
• B. The particles in the surroundings move faster and have increased entropy.
•C. The particles in the surroundings move
surroundings move slower and have increased entropy.
• D. The entropy is not affected by this.
Answer:
B. the particles in the surroundings move faster and have increased entropy
Explanation:
An exothermic process releases heat, causing the temperatures of the surroundings to increase. Entropy increases as temperature increases. Since an exothermic reaction releases heat to the surroundings, molecules in the surroundings will begin to move faster because they will absorb more energy, which increases their kinetic energy. An increase in temperatures means that the particles of the surroundings have greater kinetic energy. The faster moving particals have more disorder than particles that are moving more slowly at a lower temperature. Entropy is interpreted as the degree of disorder/randomness.
Out of a box of 46 matches, 22 lit on the first strike. What percentage of the matches in the box did not light on the first strike?
Answer: 52.17%
Explanation:
Number of matches in the box = 46
Number of matches that lit on the first strike = 22
Number of matches that did not light on the first strike = 46 - 22 = 24
Therefore, the percentage of the matches in the box did not light on the first strike will be:
= (Number of matches that did not light on the first strike / Number of matches in the box) × 100
= 24/46 × 100
= 52.17%
Therefore, the percentage of the matches in the box that did not light on the first strike is 52.17%.
When 38^88Sr decays to 34^84Kr, a(n) ______________ is emitted
Answer:
The correct answer is - alpha particle and positron.
Explanation:
In this question, it is given that, 38^88Sr decays to 34^84Kr, which means there is an atomic number decrease by 4, 38 to 34, and atomic mass decreases by 4 as well 88 to 84.
A decrease in the atomic mass is possible only when there is an emission of the alpha particle as an alpha particle is made of 2 protons and 2 neutrons. If an atom emits an alpha particle, there is a change in atomic number as it decreases by two, and its mass number decreases by four.
So after the emission of an alpha particle, the new atom would be
38^88Sr=> 36^84X => 34^84Kr
so there is also two positron emission that leads to decrease in atomic number by one with each emission:
38^88Sr=> 2^4He+ 36^84X => 36^84X + 2(1^0β+) => 34^84Kr
Positron decay is the conversion of a proton into a neutron with the emission of a positron that causes the atomic number is decreased by one, which causes a change in the elemental identity of the daughter isotope.
Why doesn’t the KHP concentration have to be exactly 0.100M? Explain using complete sentences.
Answer:
The answer is in the explanation.
Explanation:
The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.
The reaction that explain this use is:
KHP + NaOH → KNaP + H2O
where 1 mole of KHP reacts per mole of NaOH
That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added
With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.
The moles of KHP are obtained from the volume and the concentration as follows:
Volume(L)*Concentration (Molarity,M) = moles of KHP
If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.
as the balloon rises what happens to the external pressure
Answer:
As the ballon rises higher the atmospheric pressure will drop if the ballon is made of an elastic material,it will stretch to allow the gas inside it to expand
Question 6 of 10 What is the function of mitochondria? O
A. The mitochondria use sugars as fuel to produce energy.
B. The mitochondria direct the cell's activities and hold its DNA.
C. The mitochondria surround the cell and control which materials come into and out of the cell.
D. The mitochondria use sunlight to produce sugars. SUBE
Answer:
A. The mitochondria use sugars as fuel to produce energy.Explanation:
The most prominent function of mitochondria is to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration and using sugar as fuel, and to regulate cellular metabolism .
What is the mass, in grams, of one mole of any substance known as?
ОА.
atomic mass
OB.
molar mass
O C.
molecular weight
OD.
atomic number
Answer:
I think it's answer would be A
What are the characteristics of ionosphere?
Explanation:
The ionosphere is a shell of electron and electrically charged atoms and molecular that surrounds, the earth.
Which atom is abundant on earth
Answer:
Oxygen
Explanation:
Oxygen is abundant on earth
Two glasses labeled A and B had equal amounts of water. Ted heated the water in one of the glasses. He then put two drops of food coloring into each of the two glasses. The table shows the time taken by the food coloring in the two glasses to spread out.
Which of the following statements is correct?
A - The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster.
B - The water in Glass A was heated; therefore, the particles in Glass A have greater kinetic energy and move faster.
C - The water in Glass B was heated; therefore, the particles in Glass B move slower.
D - The water in Glass A was heated; therefore, the particles in Glass A move slower.
Answer:
The answer is A: The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster.
Explanation:
Think about it, if you boil water, whatever you put in the water is going to move around faster than if you put something in standing water.
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The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster. The correct answer is A.
What is food coloring?Food coloring, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink.
The food coloring we add to the water is pushed around by the water molecules. Since the molecules in warm water move around faster, the food coloring spreads out quicker in warm water than in cold water.
From the table, we can say that the water in glass B was heated by Ted and the molecules of food coloring spread out quickly in warm water and they have greater kinetic energy and move faster.
On the other hand, in glass A, the water is cold, so food coloring will not dissolve quickly.
Therefore, The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster. The correct answer is A.
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a 20.5g sample of cleaning detergent contains 8.61g of NH40H.CALCULATE the percentage composition of nitrogen in the cleaning detergent sample
Answer:
The mass percentage composition of nitrogen in the sample of the cleaning detergent is approximately 16.78%
Explanation:
The given mass of the sample of the cleaning detergent, m₁ = 20.5 g
The mass of the ammonium hydroxide, NH₄OH in the detergent, m₂ = 8.61 g
The molar mass of NH₄OH = 35.04 g/mol
The molar mass of nitrogen, N = 14.01 g/mol
Therefore, the mass, m₃ of nitrogen, N, in 8.61 g of ammonium hydroxide, NH₄OH, is found as follows;
m₃ = (14.01/35.04) × 8.61 g = (402,087/118,800) g ≈ 3.44 g
The mass of nitrogen, N, in the ammonium hydroxide, NH₄OH, contained in the 20.5 g sample of the cleaning agent, m₃ ≈ 3.44 grams
The percentage composition of nitrogen in the sample of the cleaning detergent, %N is given as follows;
[tex]\% Composition = \dfrac{Mass \ of \ component}{Total \ mass \ of \ cleaning \ detergent} \times 100[/tex]
Therefore;
%N ≈ ((3.44 g)/(20.5 g)) × 100 ≈ 16.78 %
The percentage composition of nitrogen, %N ≈ 16.78%.
How many Sodium (NA) Atoms are in Methylene?
Answer:
No Sodium(Na) in methylene
Explanation:
Methylene is an organic compound
cho hỗn hợp gồm alcl3 và fecl3 trình bày cách tách từng muối riêng ra khỏi hỗn hợp
Answer:
ném NaOH vào thì th AlCl3 tan hết còn lại kết tủa Fe(OH)3 lần.
Lọc kết tủa riêng phần dung dịch tan riêng
Rồi Cho HCl vô lại là xong
Explanation:
