Answer:
An archer's stretched bow.
Explanation:
Elastic potential energy is energy stored as a result of applying a force to deform an elastic object.
How many moles of Na2SO4 are present in 426.12 grams of Na2SO4? (5 points)
Group of answer choices
2
3
5
6
Answer: It’s 2.9 moles
Explanation:
Answer:
b) 3
Explanation:
i got it right
How many molecules of nitrogen dioxide (NO2) can be produced from 4 moles
of oxygen (O2)? *
The number of molecules of Nitrogen dioxide : = 4.816 x 10²⁴
Further explanationGiven
4 moles of Oxygen(O2)
Required
The number of molecules
Solution
Reaction
2NO + O2 ⇒ 2NO2
From the equation, mol NO2 :
= 2/1 x mol O2
= 2/1 x 4 moles
= 8 moles
The number of molecules :
= 8 x 6.02 x 10²³
= 4.816 x 10²⁴
How does the freezing point of a substance relate to its melting point?
Answer:
The melting temperature of a solid is generally considered to be the same as the freezing point of the corresponding liquid; because a liquid may freeze in different crystal systems and because impurities lower the freezing point, however, the actual freezing point may not be the same as the melting point.
#carryONlearningA 170.0 g sample of an unidentified compound contains 29.84 g sodium, 67.49
g chromium, and 72.67 g oxygen. What is the compound's empirical formula?
The empirical formula : Na₂Cr₂O₇
Further explanationGiven
170 g sample contains :
29.84 g sodium, 67.49 g chromium, and 72.67 g oxygen
Required
The compound's empirical formula
Solution
mol ratio of elements :
Na : 29.84 : 23 g/mol = 1.297
Cr : 67.49 : 51,9961 g/mol = 1.297
O : 72.67 : 16 g/mol = 4.54
Divide by 1.297
Na : Cr : O = 1 : 1 : 3.5 = 2 : 2 : 7
Scientists often need a catalyst to start a chemical reaction. They need to apply heat, acids, or other materials to jump-start the experiment.
Which phrase is the best definition of catalyst?
A. something hot
b. something acidic
c. something that triggers
d.something that is scientific
Answer:
something that triggers
Explanation:
a catalyst helps move a reaction along
A catalyst shows some specificity in its action. It speeds up only a spontaneous reaction. The best definition of catalyst is something that triggers. The correct option is C.
What is a catalyst?A substance which increases the rate of a chemical reaction without itself undergoing any permanent change chemically or quantitatively is defined as the catalyst and the phenomenon is called catalysis.
It is believed that a catalyst actually participates in the chemical reaction that is speeds up. It forms temporary bonds with the reactants yielding an intermediate activated complex.
A typical example of catalyst is iron (Fe) which is used in the Haber process for the manufacture of ammonia. The catalyst is recovered unchanged in amount and chemical composition at the end of the reaction.
In most cases, a small amount of a catalyst can speed up reaction between large amounts of reactants. A catalyst shows maximum efficiency at optimum temperature.
Thus the correct option is C.
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nuclear energy is created through the process of splitting apart atoms and releasing large amounts of heat energy that can be converted to electrical energy.this process is known as?
HURRY!!!! TIMED!!! WILL GIVE BRAINLIST!!!
A 10.0 g sample containing calcium carbonate (CaCO3) and an unreactive material was placed in excess hydrochloric acid, HCl. A reaction occurred, producing calcium chloride (CaCl2), water, and carbon dioxide. (a) write a balanced equation for the reaction (b) when the reaction was complete, 800 mL of carbon dioxide gas was collected. How many moles of calcium carbonate were used in the creation? (c) How many grams of CaCO3 were used? (d) If there was another contaminant in the sample that was not unreactive, would this have caused the percent yield of carbon dioxide to be higher, lower, or the same, explain your answer.
Explanation:
(a) write a balanced equation for the reaction
CaCO3 + HCl --> CaCl2 + H2O + CO2
The balanced equation is given as;
CaCO3 + 2HCl → CaCl2 + H2O + CO2
(b) when the reaction was complete, 800 mL of carbon dioxide gas was collected. How many moles of calcium carbonate were used in the creation?
From the balanced reaction;
1 mol of CaCO3 reacts to produce 1 mol of CO2
1 mol of CO2 = 22.4 L of CO2
This means;
1 mol of CaCO3 reacts to produce 22.4L of CO2
x mol would produce 800ml (0.8 L) of CO2
1 = 22.4
x = 0.8
x = 0.8 * 1 / 22.4 = 0.0357 mol
(c) How many grams of CaCO3 were used?
Mass = Number of moles * Molar mass
Molar mass of CaCO3 = 100.0869 g/mol
Mass = 0.0357 mol * 100.0869 g/mol = 3.57 g
(d) If there was another contaminant in the sample that was not un reactive, would this have caused the percent yield of carbon dioxide to be higher, lower, or the same, explain your answer.
The same
An un reactive contaminant in the sample is most likely a catalyst. Catalysts only affect the rate of reaction. They do not affect yields of products.
Dana is playing with her friends. They ride their scooters 20 meters down the road North. They stop to grab a drink of water. Feeling tired, they turn around and ride their scooters 20 meters south
What is Dana and her friend’s displacement
Answer:
what is the displacement
Explanation:
Someone help it’s due today
Answer:
All elements are neutral
Explanation:
The plum pudding model of the atom indicated that all elements are neutral. The model was proposed by J.J Thomson after he conducted his experiment on the gas discharge tube.
From the experiment he discovered electrons which he called cathode rays.
Therefore, he suggested the plum pudding model of the atom.
The model describes negatively charge sphere surrounded by positive charges to balance them.
How many moles of CH3 are in 60 grams of CH3 ?
Answer: There are 3.99 .
Explanation:
Metals usually bend without breaking
while gems usually break in a specific pattern. What might be happening
to the bonds between the atoms in these materials that can explain this
difference?
We have that For a metal to metal metallic bond the atoms are arranged in a very compact manner ,This help for metals to move over each other in case of a bend.While gem atom don't same attribute.
From the question we are told
Metals usually bend without breaking
while gems usually break in a specific pattern. What might be happening
to the bonds between the atoms in these materials that can explain this
difference?
Generally
Metals are elements that form positive ionsMetals tend to engage in variant types of bondsFor a metal to metal metallic bond the atoms are arranged in a very compact manner This help for metals to move over each other in case of a bend.Hence, Metals don't break upon a bendGems, on the other hand break on impact be cause of the bonding between them.Most gems use an ionic bond for the bonding mechanism
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How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions?
1. They used X-ray analysis.
2. They used litmus testing.
3. They burned the paint to examine what elements were left after the chromium was burned off.
4. They studied the density of modern yellow paint to that of 100-year-old paint.
Answer:
I think the answer is A - they used X-ray analysis.
Explanation:
Answer:They used X-ray analysis
Explanation:
It’s in the text
How many atoms are in 4.5 x 1022 moles of CO2?
The number of atoms : N = 2.709 x 10⁴⁶
Further explanationGiven
4.5 x 10²² moles of CO₂
Required
The number of atoms
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
Input the value :
N = 4.5 x 10²² x 6.02 x 10²³
N = 2.709 x 10⁴⁶
At certain times of year , the oceans get warmer. Which part of the water cycle is directly affected by the warming of the ocean water?
A water molecule is held together by ___ covalent bonds,
meaning there are a total of __shared electrons in the
molecule.
2 covalent bonds
2 pairs or 4 electrons
Wastewater filtration
Pros and cons of secondary water filtration?
How many atoms of silver are in a bracelet that has a mass of 13.94 grams?
Number of Silver atoms : N = 7.8 x 10²² atoms
Further explanationGiven
mass of bracelet : 13.94 g
Required
Number of atoms
Solution
Assuming the bracelet consists entirely of silver
mol of silver :
= mass : molar mass
= 13.94 g : 107,8682 g/mol
= 0.129
Number of atoms :
N = n x No(No = Avogadro's number)
N = 0.129 x 6.02 x 10²³
N = 7.8 x 10²² atoms
The stability of atomic nuclei is most affected by the
a)number of N
b) number of e
c) number of P
d) ratio of N to P
ASAP PLZZ
Why can single bonds rotate freely?
which element group makes computers and calculators
how many moles are in 1.2 x 10^26 molecules of calcium hydroxide
Answer:
199.26 or with sig figs 2.0 x 10^2
Explanation: you take the # of molecules and divide it by avagadros number which is 6.022141 x 10^23
According to the Heisenberg uncertainty principle, it is impossible to know both the __ and __ of an electron simultaneously.
a. mass and charge
b. position and velocity
c. mass and position
d. velocity and charge
Answer:
C
Explanation:
It's simple because there were so many quantitative analysis of error and they didn't had the kind of observations as we have now
Learning Task 2: Fill in the blanks. Write your answers
stars evolve and change over time, what is something else on earth that changes over time? describe the similarities and differences
Answer:
Trees change over time.
Explanation:
In the summer, trees thrive on the nutrients the sunlight gives them. In the winter, their leaves change colors and they start to perish. Then, with a little bit of sunlight ad water, they can thrive again. Stars also start to perish at some point, but they do not thrive again. They continue perishing until they implode.
What is the oxidation number for Cl?
2
+1
-1
+2.
Answer:
-1
Explanation:
Why are we able to see planets at night?
Answer: Because planets do not have nuclear fusion, they do not produce their own light. Instead, they shine with light reflected from a star. When we see planets in the night sky, such as Venus, the so-called "Evening Star," we're seeing reflected sunlight.
Explanation:
What causes the biggest change mass or speed?
Answer:
Explanation if an object is in motion and more force is applied to it, the object will begin moving faster. If two objects have the same mass and a greater force is applied to one of the objects, the object which receives the greater force will change speeds more quickly.:
Answer:
i think that it is F
Explanation:
PLEASE HELP ME!! CHEMISTRY
139. How many formula units are present in 500.0 g of lead (II) chloride?
Answer:
(500.0 g PbCl2) / (278.1164 g PbCl2/mol) × (6.022 × 10^23 f.u./mol) =
1.083 × 10^24 formula units
Explanation:
Which state or states of matter have fixed volume but not a fixed shape?
Answer:
gas and liquid
Explanation:
In an exothermic reaction, the average kinetic energy of the particles of matter ib the products _____
1. decreases
2.stays the same
3. increases
Answer:
decreases
Explanation:
I'm hope it's correct
When there is an exothermic reaction so here the average kinetic energy of the particles of matter ib the products is option 1. decrease.
What is an exothermic reaction?In terms of thermochemistry, an exothermic reaction means the reaction where the total standard enthalpy should change so ΔH⚬ is negative. Also it should be release heat.
So based on this, When there is an exothermic reaction so here the average kinetic energy of the particles of matter ib the products is option 1. decrease.
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