Answer:
She will have an active imagination.
Explanation:
I took the test and i got 90%
But this one is right, hope this helps ( :
Answer:
a
Explanation:
give the person above me brainlest :)
TRUE OR FALSE? Alloys are used more than pure metals because they are generally softer and less likely to react with air or water. WILL GIVE BRAINLIEST
Answer:
False
Explanation:
They’re used cause they’re generally harder than pure metals
Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...
So I would say false
Oil is removed from the refrigerator vapor by a:
A compressor, condenser, and a evaporator
Which of the following macromolecule is the main energy source for most living organisms?
A. Nucleic Acids
B. Carbohydrates
C. Lipids
D. Proteins
Answer:
Carbohydrates
Explanation:
Living things use carbohydrates as their main source of energy. The breakdown of sugars, such as glucose, supplies immediate energy for cell activities. Plants, some animals, and other organisms also use carbohydrates for structural purposes.
Short Answer Questions 18 points
1) What year was Mendeleev born? _______________________________________
2) Where was Mendeleev born? ______________________________________
3) Explain how Mendeleev arranged his periodic table.______________________________________
4) What were the 3 Elements that were missing from Mendeleev’s Periodic Table?
__________________________________________________________________
5) When did Mendeleev die? Exact date ____________________________________
6)Which particles are in the nucleus of an atom? ______________________________
1) He was born on February 8, 1834
2) He was born in Tobolsk, Russia
3) Mendeleev arranged the elements in order of increasing relative atomic mass.
4) Gallium, germanium, and scandium
5) He died on February 2, 1907
6) Protons (positive charge) and neutrons (neutral charge)
An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer: The percent yield of the reaction is 77.0 %
Explanation:
[tex]2Pb+O_2\rightarrow 2PbO[/tex]
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]
[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]
According to stoichiometry:
2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]
2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]
Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]
percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]
The three lines in this Lewis dot structure represent the.
A)
three valence electrons of dinitrous oxide.
B)
six electrons in the triple bond of diatomic nitrogen.
C)
three electrons joining two nitrogen atoms in a diatomic molecule.
D)
three double bonds between the valence electrons of diatomic nitrogen.
Answer:
B) . six electrons in the triple bond of diatomic nitrogen
Explanation:
The three line in this Lewis dot structure represents the six electrons in the triple bond of diatomic nitrogen.
Nitrogen is made up of 7 electrons with 5 valence ones.
A lewis structure is made up of the symbol of the element surrounded by dot to represent the valence electrons.
In this nitrogen molecule, both species share 6 electrons. This makes each nitrogen atom isoelectronic with neon.
Question 2 of 25
Rain exists in which phase?
O A Liquid
O B. Solid
C. Plasma
D. Gas
Answer:
liquid
Explanation:
correct answer hope it helps
Why do you need to use soap when you wash oil from your hands
Answer:
Germs stick to the oil on your hands, and washing with just water doesn't work because oil and water don't mix, but soap dislodges the germs and oil from your hands
Explanation:
Answer:
You need soap to wash the oil off your hands because oil and water don't mix well and makes it difficult to remove
Explanation:
A. filtration B. sieving C. using a magnet D. decantation
E. evaporation
Directions: Choose the best technique that can be used to separate the substances or
materials in each mixture. Write the letter of your answer on the space before the nu
1. Cornstarch and water
2. Iron and sulfur
3. Rice grains and stones
4. Pebbles and soil
5. Muddy water
6. Ground pepper and water
7. Flour and coarsely ground corn
8. Needles in a box of beads
9. Sesame seeds in soy sauce
10. Pebbles and iron nails
11. Fine sand from rocks
12. Sand from water
13. Gravel and sand
14. Salt and iron filings
15. Pins from assorted buttons
16. Coconut oil from coconut milk
17. Sand and pebbles
18. Pasta from water
19. Sand and thumb tacks
20. Salt solution
Answer:
Explanation:
1. Cornstarch and water - decantation
2. Iron and sulfur
3. Rice grains and stones - sieving
4. Pebbles and soil - decantation
5. Muddy water - decantation
6. Ground pepper and water - decantation
7. Flour and coarsely ground corn - sieving
8. Needles in a box of beads - using a magnet
9. Sesame seeds in soy sauce -
10. Pebbles and iron nails - using a magnet
11. Fine sand from rocks - sieving
12. Sand from water - filtration
13. Gravel and sand - sieving
14. Salt and iron filings - sieving
15. Pins from assorted buttons - using a magnet
16. Coconut oil from coconut milk - filtration
17. Sand and pebbles - sieving
18. Pasta from water - sieving
19. Sand and thumb tacks - using a magnet
20. Salt solution - filtration
What is one example of chemical weathering affecting a rock
Answer:
one example of chemical weathering is when carbon dioxide mixes with water.
Explanation:
when dioxide mixes with water it creates carbonation.
Which of the following statements is true regarding both theories and laws?
A: Change over time
B: Cannot be proven
C: Require consensus
D: Supported by observations
Answer:
D. Supported by observations
Explanation:
Because theories change over time, they both need to be proven, they do not go off of consensus, but they do need to be supported by observations.
HOPE IT HELPS❣️
Pls pls pls pls pls pls help
The reaction of zinc metal and hydrochloric acid produces hydrogen gas and zinc chloride. Write the balanced chemical equation. Phases are optional.
Answer:
Zn + 2HCl -----> ZnCl₂ + H₂
Explanation:
The balanced chemical equation for Zn with hydrogen is Zn + 2HCl ---> ZnCl₂+ H₂.
What is balanced chemical equation?
A balanced chemical equation is one in which number of reactant is equal to number of products. When Zinc reacts with hydrogen it will form zinc chloride and hydrogen gas.
Here, 1 molecules of hydrochloric acid are participating in the process, and 1 molecules of hydrogen are being created.
Therefore, The balanced chemical equation for Zn with hydrogen is Zn + 2HCl ---> ZnCl₂+ H₂.
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Why does the flask have to be closed during the hydrochloric acid and sodium carbonate reaction?
Answer:
The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
Explanation:
The hydrochloric acid and sodium carbonate reaction was exothermic that caused the pressure to decrease. The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
In exothermic reactions, energy is produced in the form of heat or light.
How many grams of Ag2CO3 will precipitate when excess Na2CO3 solution is added to 40.0 mL of 0.679 M AgNO3 solution
Answer:
The answer is "[tex]37.45364 \ g[/tex]"
Explanation:
Equation:
[tex]2AgNO_3 (aq) + Na_2CO_3 (aq) \longrightarrow Ag_2CO_3 (s) + 2NaNO_3 (aq)[/tex]
Calculating the mol of [tex]AgNO_3[/tex]:
[tex]\to V = 40.0 mL\\\\[/tex]
[tex]= 40.0 \times 10^{-2} \ L \\\\[/tex]
[tex]\to n = Molarity \times Volume \\\\[/tex]
[tex]= 0.679 \times 40.0 \times 10^{-2}\\\\= 27.16 \times 10^{-2} \ mol[/tex]
mol of [tex]Ag_2CO_3= \frac{1}{2} \times n\\\\[/tex]
[tex]= \frac{1}{2} \times 27.16 \times 10^{-2}\\\\= 13.58 \times 10^{-2}\\\\[/tex]
Calculating the molar mass of [tex]Ag_2CO_3[/tex],:
[tex]= 2\times MM(Ag) + 1 \times MM(C) + 3 \times MM(O)\\\\= 2 \times 107.9 + 1 \times 12.01 + 3 \times 16.0\\\\= 275.81 \ \frac{g}{mol}[/tex]
Calculating the mass of [tex]Ag_2CO_3[/tex],
[tex]m = mol \times molar \ mass[/tex]
[tex]= 13.38 \times 10^{-2}\ mol \times 2.758 \times 10^2 \ \frac{g}{mol}\\\\= 37.45364 \ g[/tex]
A commonly held idea about influenza is that it is a disease that occurs primarily in cold weather. Doctors report incidences of illness, such as influenza, to the Centers for Disease Control (CDC). The graph below shows data for three flu seasons. Note that this graph shows data from October, week 40, of one year to July, week 28, of the following year.
Which evidence supports this idea?
The graph line for 2008-09 has the highest peaks for flu.
All three graph lines show different patterns throughout the year.
The graph line for 2008-09 has a peak in week 44.
All three graph lines peak over the same few weeks of winter.
Answer:
D.All three graph lines peak over the same few weeks of winter.
Explanation:
took the test
PLEASE HELP!! I WILL MARK THE 1st ONE BRAINLIEST!
Answer:
I hope you do well on the test good luck
Explanation:
Which one of the following is NOT a proper unit for frequency? *
m·s–1
Hz
s–1
1/s
Answer:
m*s⁻¹.
Explanation:
Hello!
In this case, since the frequency measures how repetitive an event is per unit of time, for instance the laps a car drives every 5 minutes or something similar, we can infer it has units of event/time; in such a way, the unit m*s⁻¹ is not a proper unit of frequency because it is a proper unit of velocity which is the distance traveled per unit of time.
In such a way, Hz (hertz), s⁻¹ and 1/s are possible ways frequency can be represented.
Best regards!
How does the VSEPR theory explain molecular shape?
A. Valence electrons modify core electron orbitals.
B. Intermolecular forces distort electron bonds.
C. Electron pair attractions pull atoms together.
D. Electron pairs repelling each other push atoms apart.
Answer:
D. Electron pairs repelling each other push atoms apart
Explanation:
Hope this helps :) I just got it wrong on ap3x so I'm sure this is right
The VSEPR theory explain molecular shape by stating that the Electron pairs repelling each other push atoms apart. Hence, Option (D) is correct
What is VSEPR theory ?
Valence shell electron pair repulsion (VSEPR) theory, is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms.
It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Nyholm.
Therefore, The VSEPR theory explain molecular shape by stating that the Electron pairs repelling each other push atoms apart. Hence, Option (D) is correct.
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Draw and name the structures of the carboxylic acids and esters you put together using molecular models.
Answer:
This question is incomplete
Explanation:
However, when the carboxylic acids and esters put together are obtained, the procedure below can be followed in drawing and naming them.
For carboxylic acid,
1) it should be noted that the functional group here is -COOH which is drawn as -C = OH
|
OH
2) The carbon of the functional group is included among the carbon to be counted when naming the structure. For example, the compound below is propanoic acid.
CH₃CH₂COOH - As you can see that there are 3 carbons linked chain there.
3) As can be seen in (2) above, the suffix "oic" is used to name carboxylic acids
4) The carbon chain here is saturated (meaning there is no double or triple bond within the carbon chain)
Example of a structure of carboxylic acid is
H₃C - CH₂ - CH₂ - C = OH
|
OH
The structure above is a butanoic acid
For ester
1)The functional group here is -COO- . which can be drawn as
- C = O
|
O -
(meaning one oxygen atom is double bonded to the carbon and the other oxygen atom is bonded to another carbon chain)
2) The alkyl group attached to the oxygen atom is first of all mentioned before the carbon chain attached from the left is mentioned. For example, CH₃CH₂CH₂COOCH₂CH₃ is ethyl butanoate
3) As seen from (2) above, the suffix "oate" is used to end the name of esters
4) As also seen from (2) above, the carbon of the functional group is also included while counting the carbon chain of the parent name (butanoate).
5) The carbon chains here are also saturated.
Example of this ester is
CH₃CH₂C = O
|
O - CH₂CH₃
The name of this compound is ethyl propanoate
Why is it necessary to add concentrated HCl, then water, rather than a solution of HCl to the eudiometer tube
If we add water to a concentrated acid, then the solution may boil very violently, splashing concentrated acid. If add acid to water, the solution that forms is very dilute and a small amount of heat is released.
Why do we add acid to water?When a strong acid is poured into water, it flows down the flask and mixes much better, so no boiling takes place. The addition of water to acid forms an extremely concentrated solution of acid initially. A large amount of heat is released and the solution may boil very violently, splashing concentrated acid out of the beaker and all this because the reaction is exothermic in nature.
The reason this takes place is due to a large amount of energy liberated in the hydration reaction of concentrated ions. Therefore, we add acid to water dropwise for the dilution with constant stirring and not water to acid directly.
If we add water to acid, then an exothermic reaction occurs and the solution may boil very violently. To form the dilute solution of any strong acid, you should add acid to water and the small amount of heat released is not sufficient to vaporize and spatter it.
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The critical resolved shear stress for a metal is 35 MPa. Determine the maximum possible yield strength (in MPa) for a single crystal of this metal that is pulled in tension.
Answer:
The maximum possible yield strength for a single crystal is 70 MPa.
Explanation:
To find the maximum possible yield strength for a single crystal we need to use the following equation:
[tex]\sigma_{y} = \frac{\tau_{CRSS}}{m_{max}}[/tex]
Where:
[tex]m_{max}[/tex] is the maximum value for Schmid factor
[tex]\tau_{CRSS}[/tex] is the critical resolved shear stress = 35 MPa
[tex] \sigma_{y}[/tex] is the yield strength =?
The Schmid factor is given by:
[tex]m = cos(\phi)cos(\lambda)[/tex]
And its maximum value is obtained when λ = 45° and Φ = 45°, so:
[tex] m = cos(45)cos(45) = 0.5 [/tex]
Finally, the maximum possible yield strength is:
[tex]\sigma_{y} = \frac{\tau_{CRSS}}{m_{max}} = \frac{35 MPa}{0.5} = 70 MPa[/tex]
Therefore, the maximum possible yield strength for a single crystal is 70 MPa.
I hope it helps you!
Type in the name of the following compounds. Be sure to use the periodic table if needed.
Answer: Sulfuric Acid
Explanation: correct on edg
Answer:
Sulfuric Acid
Explanation:
correct on edg
What happens in a chemical reaction?
a. Atoms are destroyed.
b. Atoms are created.
c. Molecules are created.
d. Atoms are rearranged.
Please select the best answer from the choices provided
A
B
С
D
Pls help please :((
Answer:
During the reaction, chemical bonds break in the reactants and new chemical bonds form in the products.
Answer:
d. Atoms are rearranged.
Explanation:
Answer them please thanks
Answer:
(3) sorry if I'm wrong
7. (1-fertilization [sorry if wrong again]
8. (4-mitosis
Explanation:
I'm learning about this right now...Sorry if I'm wrong but I'm pretty sure they're right! Hope this helps tho! if I'm right maybe mark me brainliest?
PLEASE HELP ME!!!!!!!!!!!!!!!!!!!
WRITE A SHORT PASSAGE ON HOW FIBRES ARE SPUN
HELPPP WILL MARK AS BRAINLIEST
Answer: Spun yarn is made by twisting staple fibers together
To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.
Explanation:
PLEAE HELP ASAP WILL MARK BRAINLYLIST! Question 2 the answers are under 2
Answer:
Alkali Metals
Explanation:
They're the most reactive elements in group one.
Trinitrotoluene (TNT, C7H5N3O6) undergoes complete combustion according to the following balanced chemical equation:
C7H5N3O6(s)+214O2(g)→7CO2(g)+32N2(g)+52H2O(l)
If 25.7 g of TNT is combusted in a 0.500 L container filled with O2 at a pressure of 7.02 bar and a temperature of 298 K, calculate the maximum mass of CO2 that could be produced.
Answer:
[tex]m_{CO2}=8.33gCO2[/tex]
Explanation:
Hello.
In this case, since the chemical reaction is:
[tex]C_7H_5N_3O_6(s)+\frac{21}{4} O2(g)\rightarrow 7CO_2(g)+\frac{3}{2} N_2(g)+\frac{5}{2} H_2O(l)[/tex]
Thus, since we have the initial moles of TNT:
[tex]n_{TNT}=25.7g*\frac{1mol}{227.13g} =0.113mol[/tex]
And the initial moles of oxygen given the ideal gas equation:
[tex]n_{O_2}=\frac{6.93atm*0.5L}{0.082\frac{atm*L}{mol*K}*298K}=0.142molO_2[/tex]
Given the 1:7 mole ratio between TNT and carbon dioxide and the 21/4:7 mole ratio between oxygen and carbon dioxide, we compute the yielded moles by each reactant:
[tex]n_{CO_2}^{by\ TNT}=0.113molTNT*\frac{7molCO_2}{1molTNT}=0.791molCO_2\\\\ n_{CO_2}^{by\ O_2}=0.142molO_2*\frac{7molCO_2}{21/4molO_2}=0.189molCO_2[/tex]
Thus, since oxygen yields less moles of carbon dioxide than TNT, we infer it is the limiting reactant, therefore, the produced mass of carbon dioxide is:
[tex]m_{CO2}=0.189molCO2*\frac{44.01gCO2}{1molCO2}\\\\m_{CO2}=8.33gCO2[/tex]
Best regards!
How does Newton’s second law apply to the golf tee balanced on the hoop? How does Newton’s second law apply to the golf tee when the hoop is pulled away?
please answer asap
There are total three laws of newtons, first law of newtons, second law of newton and third law of newton. Therefore, when a golf club is subjected to an imbalanced force, its velocity changes, which is according to newton’s second law.
What is newton's second law?According to Newton's Second Law of Motion, acceleration (gaining speed) occurs when a force acts on a mass (object). Riding a bicycle is a great example of this rule of motion in action. The mass is represented by your bicycle. The force is generated by your leg muscles pulling on the pedals of your bicycle.
The ball remains balanced on the tee due to the balanced forces of gravity downhill and upward. Force equals mass multiplied by acceleration (f=ma). When a golf club is subjected to an imbalanced force, its velocity changes.
Therefore, when a golf club is subjected to an imbalanced force, its velocity changes, which is according to newton’s second law.
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A Barometer reads 29.1 inches of mercury.Calculate this pressure in mmHg.
What is the answer?
This follows a simple conversion technique. Basically what the question is trying to say here is to convert 29.1 inHg to mmHg. 1 inHg is equal to 25.4 mmHg so 29.1 inHg would be equal to [tex]25.4 * 29.1[/tex] which when evaluated turns out to be: [tex]739.14[/tex]. :D
The pressure will be 739.14 mm Hg.
What is pressure?The SI unit measuring pressure would be the pascal, which measures the force of each unit area of the surface.
Calculation of pressure
It is known that 1inHg = 25.4 mm Hg.
Hence, the pressure = 25.4 × 29.1 = 739.14 mm Hg
Therefore, the pressure will be 739.14 mm Hg.
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