Answer:
D
Explanation:
If there are 2 of the same rocks on two continents, that shows that they were once merged. If there is glacial existence in places where glaciers would’ve melted (Like Africa has glacial existence from Antarctica ) this shows that continents were once merged. If life forms preserved as fossils were matched on 2 different continents this shows that all the continents were once merged.
Answer:
so i am doing this and i need help what did u get for number 1
Explanation:
its the first question
2.
Corona virus has a spherical shape. Its diameter is approximately 120 nm. How
many of them can sit side by side to form a circle around a piece of human hair.
Take the diameter of a hair as 50 um. (Select the nearest value to your calculation
result)
a) 1.23x10 12
b) 4.45 x106
C) 1312
d) 417
Answer:
417
Explanation:
50um is
50000nm
50000:120=417
Blast furnaces extra pure iron from the iron(III) oxide in iron ore in a two step sequence. In the first step, carbon and oxygen react to form carbon monoxide: 2C + O2--------- 2CO In the second step, iron(III) oxide and carbon monoxide react to form iron and carbon dioxide: Fe2O3 + 3CO ------- 2Fe + 3CO2Suppose the yield of the first step is and the yield of the second step is 79%. Calculate the mass of oxygen required to make 10g of Iron. Be sure your answer has a unit symbol, if needed, and is rounded to the correct number of significant digits.
Answer:
The mass of O2 that will produce 10 g of Iron, Fe is 6.0 g
Note: The question is missing some details. The complete question is given below:
Blast furnaces extra pure iron from the iron (III) oxide in iron ore in a two step sequence. In the first step, carbon and oxygen react to form carbon monoxide 2C(s)+O2(e) -2CO(« In the second step, iron(III) oxide and carbon monoxide react to form iron and carbon dioxide Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3CO2(g) Suppose the yield of the first step is 90.% and the yield of the second step is 79.%. Calculate the mass of oxygen required to make 10 g of iron. Be sure your answer has a unit symbol, if needed, and is rounded to the correct number of significant digits.
Explanation:
Equation for the two reactions is given below:
Step 1: 2C(s) + O2(g) → 2CO(g)
Step 2: Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g)
In the second step 3 moles of CO reacts to produce 2 moles of Fe
Molar mass of CO = 28 g/mol, molar mass of Fe = 56 g/mol
Therefore, 84 g (3 × 28) of CO will produce 112 g (2 × 56) of Fe
10 g of Fe will be produced by 84/112 × 10 g of CO = 7.5 g of CO
However, the actual yield is 79%, therefore, 7.5 g of CO will produce 0.79 × 10 g of Fe = 7.9 g of Fe
Mass of CO that will produce an actual yield of 10 g of Fe = 7.5/7.9 × 10 = 9.50 g of CO
From the first step:
1 mole of O2 reacts to produce 2 moles of CO (molar mass of O2 = 32 g)
32 g of O2 produces 56 g (2 × 28 g) of CO
Mass of O2 that will produce 9.50 g of CO = 32/56 × 9.50 g = 5.43g
However, since the actual yield is 90%, therefore, mass of CO produced = 0.9 × 9.50 = 8.55 g of CO
Mass of O2 that will produce 9.50 g of CO = 5.43/8.55 × 9.50 g = 6.03 g
Therefore, mass of O2 that will produce 10 g of Iron, Fe is 6.0 g
Calculate the pH for the following buffer solutions with steps.
1. 7.4862 grams of acetic acid and 10.4695 grams of sodium acetate are dissolved in enough deionized water to make 250.0 mL of solution.
2. 11.8115 grams of trimethylamine and 18.7088 grams of trimethylammonium chloride are dissolved in enough deionized water to make 500.0 mL of solution.
Thank You:)
Answer:
Answer is shown on the paper :D
Explanation:
Remember to follow sig-figs.
A large balloon contains 5400 m3 of He gas that is kept at a temperature of 280 K and an absolute pressure of 1.10 x 105 Pa. Find the mass of He inside the balloon. (Molar mass of He : 4.002 g/mol)
Answer:
1.02 × 10⁶ g
Explanation:
Step 1: Given data
Volume of the balloon (V): 5400 m³Temperature (T): 280 KAbsolute pressure (P): 1.10 × 10⁵ PaMolar mass of He (M): 4.002 g/molStep 2: Convert "V" to L
We will use the conversion factor 1 m³ = 1000 L.
5400 m³ × 1000 L/1 m³ = 5.400 × 10⁶ L
Step 3: Convert "P" to atm
We will use the conversion factor 1 atm = 101325 Pa.
1.10 × 10⁵ Pa × 1 atm / 101325 Pa = 1.09 atm
Step 4: Calculate the moles of He (n)
We will use the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 1.09 atm × 5.400 × 10⁶ L / 0.08206 atm.L/mol.K × 280 K
n = 2.56 × 10⁵ mol
Step 5: Calculate the mass of He (m)
We will use the following expression.
m = n × M
m = 2.56 × 10⁵ mol × 4.002 g/mol
m = 1.02 × 10⁶ g
whats the answerrrr giving brainliest
Please help ASAP!! i'll give you 100 point just to help me with this! 1-What places do the colors go. 2-Where do the words go. 3-Where do the arrows go. BTW this subject is Science.
Answer:
You have to put equator in middle, trade winds on which ever side they are trading the items on, probaly north, and westerlies west, and jet streams around blue at the bottom, red at top and green in the middle.
Explanation:
I cant really explain it right because I don't know how to put the picture. I mean paste the picture on here
CAN YOU TELL ME HOW TO PUT PICTURE
How many Joules of heat would be required
completely melt 5.00 grams of H2O(s) at 0°C at to
H2O(C) at 0°C?
Heat would be required : 1,670 J
Further explanationGiven
mass of H₂O=5 g
Required
Heat to melt
Solution
The heat to change the phase can be formulated :
Q = m.Lf (melting/freezing)
Lf=latent heat of fusion
The heat of fusion for water at 0 °C : 334 J/g
Input given values in formula :
[tex]\tt Q=5\times 334=\boxed{\bold{1,670~J}}[/tex]
As the temperature of a gas increases with the volume remaining constant, the pressure of the gas A) decreases B) increases C ) remains the same
Answer:
B) increases
higher temperature = higher pressure
Why does powdered calcium carbonate react faster with hydrochloric acid than calcium carbonate chips?
Answer:
Exposed surface area
Explanation:
The powdered calcium carbonate will react faster with hydrochloric acid than calcium carbonate chips due to the exposed surface area.
Powdered calcium carbonate has a larger surface area compared to the chips. And, the larger the surface area exposed on a body, the faster the reaction it will undergo.
For the same masses of a solid substance, the smaller the particle size of each form, the larger the surface area exposed to reaction.
The surface area exposed proportionally affects the rate of reaction.
Genetically engineered crops (3 points)
A. are often unsuccessful
B. create optimum soil
C. increase crop yields
D. prevent weed growth
Answer:
C. increase crop yields
Explanation:
Genetically modified organisms are those organisms that have been improved using genetic engineering procedures. Genetic engineering/modification is the manipulation of an organism's genome in order to get an improved organism with desirable traits.
The organisms being genetically modified or engineered is called GMO or transgenic organisms. Hence, in this case, one feature of the crops being genetically modified is to have an INCREASED YIELD.
organic chemical used to preserve biological specimens is organic compound or hydrocarbons
Answer:
hydrocarbons
Explanation:
hope this is right.. if not sorry:)
What type of reaction is P4 + 3O2 = 2P2O3
Answer:
synthesis
Explanation:
hope this helps
The given reaction is a type of synthesis reaction.
• The reactions, which takes place when two distinct molecules or atoms associate to produce a distinct molecule or compound is known as synthesis reactions.
• The synthesis reactions are one of the prime categories of chemical reactions that comprise combustion reactions, single displacement, and double displacement reactions.
• In synthesis reactions, energy is released and the reaction is exothermic, in some cases, endothermic is also possible.
• In the given reaction atoms of phosphorus and oxygen combines to produce the compound phosphorus oxide.
Thus, the given case is an example of synthesis reaction.
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A student has 2 rubber balls of the same size and weight. Ball A is still and Ball B is rolling.Ball B hits Ball A, and Ball A start moving. Why does Ball A start moving?
Answer:
It starts to move because of Newtons first law "An object will not change it's motion unless a force acts on it"
Explanation:
Meaning ball B is that force acting upon ball A
In a balanced chemical equation the mass of the reactants and products are equal.
True
False
A balanced chemical equation obeys the law of conservation of mass. In a balanced chemical equation the mass of the reactants and products are equal. The correct option is true.
What is a balanced chemical equation?A chemical equation in which the number of atoms of reactants and products on both sides of the equation are equal is defined as the balanced chemical equation. The numbers which are used to balance the chemical equation are called coefficients. They are found in front of formulas.
According to law of conservation of mass, mass can neither be created nor be destroyed. But it can be transformed from one form to another.
In a balanced chemical equation, the total mass of the reaction remains constant. The mass of the reactants before reaction is equal to the mass of products after reaction.
Thus the given statement is true.
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PLEASEEEEEEEEEEEE HELP 100 POINTS PLEASEEEE Sofia has two 10-gram samples of sea salt. One sample is finely ground into thousands of tiny grains of salt. The other sample is a single block of salt crystals. Sofia tries to dissolve each sample in a separate glass of water. Which sample will dissolve first?
A.the finely ground sample because it has more surface area
B.the single block because it has more surface area
C.the single block because it has less surface area
D.the finely ground sample because it has less surface area
Answer:
the answer is D to this question
The capability of a gaseous, solid or liquid component to dissolve in the solvent to yield a solution is called solubility. Solubility depends on the exterior area of the substance.
The correct answer is:
Option A. The finely ground sample because it has more surface area.
This can be explained as:
The rate of desolvation of the solute is dependent on the surface area of the solute.The grounded particle of a substance dissolves faster as compared to the large particles.The solubility of solute depends on the surface area. The large surface area of compounds increases the contact rate of solute with the solvent.Therefore, the finely ground sample will dissolve fast.
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if an endothermic reaction begins at 26°C and decreases by 2°C per minute how long will it take to reach 0°C?
Answer:
13 minutes
Explanation:
For the endothermic reaction to reach 0°C, it will take 13 minutes.
Let us follow the process step by step;
Rate of decrease is 2°C per minute.
Start is 26°C
Time temperature
0 min 26°C
1 min 24°C
2 min 22°C
3 min 20°C
4 min 18°C
5 min 16°C
6 min 14°C
7 min 12°C
8 min 10°C
9 min 8°C
10 min 6°C
11 min 4°C
12 min 2°C
13 min 0°C
calculate h30+ for a 8.86*10^3 hbr solution
[H₃O⁺] = 8.86 x 10³ M
Further explanationThe dissociation of water :
H₂O(l)⇒H⁺+OH⁻
Hydrogen ions H⁺ bond with H₂O to form H₃O⁺ ions(hydronium ion)
When acid(Hbr acid) is in the presence of water(dissociates), the H⁺ ions bond with water molecules to form hydronium, the reaction :
HBr(aq)+H₂O→H₃O+(aq)+Br−(aq
So Ionization of HBr :
[tex]\tt HBr\rightarrow H_3O^++Br^-[/tex]
[HBr]= 8.86 x 10³,
From equation ratio [H₃O⁺] : HBr = 1 : 1, so
[tex]\tt [H_3O^+]=8.86\times 10^3[/tex]
What characteristic odor would you expect to observe if an alcohol reacted with acidified ethanoic acid?
a. A vinegar-like smell.
b. None.The product would be odorless.
c. A rotten fruit smell.
d. A fruity smell.
Nazeeh conducted an experiment to demonstrate the law of conservation of matter. He burned a strip of magnesium that had a beginning mass of 5.0 g over an open flame. The magnesium gave off a bright white light and smoke as it was being burned. The white ash that was left over had a mass of 4.5 g. Nazeeh concluded that his experiment did not uphold the law of conservation of matter.
What did Nazeeh NOT take into consideration when drawing his conclusion?
A
that some of the mass was lost to the air as light
B
that mass has absolutely no relationship to matter
C
that some of the mass was lost to the air as smoke
D
that ash has a lower mass than the strip of magnesium
Answer:
C
that some of the mass was lost to the air as smoke
Answer:
C
Explanation:
A: Light isn´t part of the mass of magnesium, light is energy, it doesn´t occupate space.
B: Mass clearly have a relationship with matter, if you increase the amout of mass, you will increase the amout of matter, one way or another.
C: It is correct, some of the mass was lost because hot gases tend to go up.
D: Yes, the ash has a lower mass than magnesium, but it is not because ash is lighter or something like that. It is because some of the ash was lost due to the air.
Identify the element in group 15, period 3 by drawing a Lewis Dot Structure
Answer:
Phosphorus
Explanation:
Lewis Dot Structure is a structural representation of a molecule that shows valence electrons of a molecule.
The element in group 15, period 3 is Phosphorus (P). Phosphorus has an atomic number 15 and valence electrons are 5. So, the lewis structure will show 5 dots around P atom.
The mass of magnesium ions in 1 kg of sea water is 1.3 g.
The concentration in parts per million (ppm) is
a 1.3x10^6
b 1.3x10^3
c 1.3x10^-3
I dont understand how to do this question. Help would be much appreciated!
Answer:
1300 ppm
Explanation:
for ppm, calculate fractional ration =(part/total) and multiply by 1 x 10⁶ => ppm
for ppb, calculate fractional ration =(part/total) and multiply by 1 x 10⁹ => ppb
Parts Per Million (ppm)
Given 1.36g in 1Kg (=1000g) => fractional ratio = (1.3g/1000g)(10⁶) = 1300 ppm
Parts Per Billion (ppb)
or if ppb is needed do the same calculation but multiply by 10⁹ ... That is,
Given 1.36g in 1Kg (=1000g) => fractional ratio = (1.3/1000g)(10⁹) = 1300000 ppb = 1.3 x 10⁶ ppb
Parts per Hundred (pph) is the same as percent (%) ... Calculate fractional ratio and then multiply by 100%
Given 1.36g in 1Kg (=1000g) => fractional ratio = (1.3g/1000g)(100%) = 0.13%
A gaseous mixture of 1.0 mol of 12 and 1.0 mol of H2 was placed in an empty vessel that has a
volume of 2.0 L. The system was allowed to reach dynamic equilibrium at 300°C.
a) State briefly what happened to the initial concentration of 12 and H2 as the reaction reaches
equilibrium
b) Does the reaction stoop at equilibrium? Why?
Answer:
See detailed explanation.
Explanation:
Hello!
In this case, for the reaction:
[tex]I_2+H_2\rightleftharpoons 2HI[/tex]
It is known that the equilibrium constant tends to be greater than 1; therefore, it is a reaction that tends to go rightwards towards the formation of hydrogen iodide.
a) Here, since the reaction tends to form the product, it is clear that the initial concentration of iodine and hydrogen will decrease as the reaction reaches equilibrium in order to increase the concentration of hydrogen iodide.
b) Yes, it stops at the point in which the following expression:
[tex]\frac{[HI]^2}{[I_2][H_2]}[/tex]
Equals the equilibrium constant.
Best regards!
What is the frequency of green light
that has a wavelength of 531 nm? (c
= 3.00 x 108 m/s)
We are given:
Wavelength of Green light (λ) = 531 nm OR 531 * 10⁻⁹ m
Speed of light (c) = 3* 10⁸ m/s
Solving for the Frequency of the wave:
We know the relation:
c = νλ
(where ν is the frequency, c is the speed of light and λ is the wavelength)
3*10⁸ = ν*(531*10⁻⁹)
ν = 3*10⁸ / 531*10⁻⁹ [dividing both sides by the wavelength]
ν = 3*10⁸*10⁹ / 531 [ since a⁻¹ = 1/a]
ν = 3*10¹⁷ / 531 [ since mᵃ * mᵇ = mᵃ⁺ᵇ]
ν = 10¹⁷ / 177
ν = 1000 * 10¹⁴ / 177 [we split the numerator to simplify]
ν = 5.65 * 10¹⁴
Hence, the frequency of Green light is 5.65 * 10¹⁴ Hz
Answer:
f = 5.6×10¹⁴ Hz
Explanation:
Given data:
Wavelength of green light = 531 nm (531×10⁻⁹ m)
Frequency of green light = ?
Solution:
Formula;
Speed of wave = wavelength × frequency
Speed of wave = 3.00×10⁸ m/s
by putting vales,
3.00×10⁸ m/s = 531×10⁻⁹ m × f
f = 3.00×10⁸ m/s / 531×10⁻⁹ m
f = 0.0056×10¹⁷ s⁻¹
f = 5.6×10¹⁴ Hz (Hz = s⁻¹)
How many unpaired electrons does calcium have? You may need to draw the orbital filling diagram for the last sublevel that contains electrons.
A) 0
B) 2
C) 4
D) 1
Answer:
0
Explanation:
Ca has 20 electrons
2
5
Calculate the number of atoms in 0.551 gram of potassium (K
I
Is: 11
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23
Answer:
8.51 x 10²¹ atoms
Explanation:
Given parameters:
Mass of K = 0.551g
Unknown:
Number of atoms = ?
Solution:
To find the number of atoms in this given substance, we need to solve for the number of moles first.
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Now;
Molar mass of K = 39g/mol
Number of moles = [tex]\frac{0.551}{39}[/tex] = 0.014mole
Therefore,
1 mole of a substance contains 6.02 x 10²³ atoms
0.014 mole of K will contain 0.014 x 6.02 x 10²³ = 8.51 x 10²¹ atoms
can someone please help me with this....?
Answer:
Explanation:
The answer is D
A sample of Neon and Helium gases at 298 K have a total pressure of 29 atm. If the partial pressure of He is 6 atm, what is the mole fraction of neon?
how many atoms of San are in 0.796 moles of this element
Answer:
4.8× 10²³ atoms
Explanation:
Given data:
Number of moles of San element = 0.796 mol
Number of atoms present = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
0.796 mol × 6.022 × 10²³ atoms / 1mol
4.8× 10²³ atoms
HURRY!!!!!!!!!!!!!!!!
When James sprayed liquid deodorant under his arm, the spot felt cold. Which sentence best explains why? A. The deodorant evaporates as it absorbs thermal energy from James’s skin. B. The deodorant condenses as it absorbs thermal energy from James’s skin. C. The deodorant evaporates as it transfers thermal energy to James’s skin. D. The deodorant evaporates as it absorbs temperature from James’s skin. E. The deodorant is a liquid that freezes at room temperature and pressure.
Answer:A. The deodorant evaporates as it absorbs thermal energy from James’s skin.
Explanation:
Naming Ionic Compounds.
What is the neutral Ionic Compound name of Be^+2 & S^-2?
What is the neutral Ionic Compound name of Pb^+2 & CO3^-2?
Answer:For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion. For example, KCl, an ionic compound that contains K+ and Cl- ions, is named potassium chloride.
Explanation: