Answer:
c
Explanation:i got it right ony my test
5-O selênio e o enxofre pertencem à família VI A da tabela periódica. Sendo assim, o seleneto e o
sulfeto de hidrogênio são representados, respectivamente pelas fórmulas:
a) HSe e HS
b) H 2 Se e HS
c) HSe e H 2 S
d) H 2 Se e H 2 S
e) H 3 Se e H 3 S
Answer:
Opção D está correta
Explanation:
Conforme indicado no parágrafo -
o selênio e o enxofre pertencem à família VI A da tabela periódica
Seleneto de hidrogênio - H2Se
Sulfato de hidrogênio - H2S
Portanto, a opção D está correta
PLEASE HELP ASAP NO LINKS PLEASE
What is the force that keeps the planets in perfect orbit around the sun?
A) Velocity
B) Gravity
C) Centrifugal Force
D) Magnetism
Answer:
gravity
Explanation:
Gravity is the force that pulls us to the surface of the Earth, keeps the planets in orbit around the Sun and causes the formation of planets, stars and galaxies.
Hope this helped!!!
Which applies to fusion? Check all that apply.
involves the splitting of nuclei
takes place in the Sun
releases radiation as a waste product
occurs in nuclear power plants and is used to generate electricity
plays a role in the production of essentially all elements heavier than helium
releases large amounts of energy
Answer: B, E, and F
Explanation: It showed the correct answer after i got it incorrect. (E2021)
Answer:
A
B
D
E
Explanation:
GOT IT RIGHT ON MY ASSIGNMENT
What is the maximum amount in moles of P2O5 that can theoretically be made from 240 g of O2 and excess phosphorus?
Answer:
hope it will help you out :)
True or False: Strong HYDROGEN bonds cause surface tension.
Choose
True or False: Many polar substances are soluble in water.
True or False: Cohesion and adhesion contribute positively to the capillary action property of water.
True or False: Water's molecular shape is trigonal planar.
True or False: Most water on earth is found in the liquid form.
True or False: Surface Tension makes it possible for some insects to walk
on water.
True or False: Capillary action is how tall trees get water from the leaves TO the roots.
True or False: Water has the density of 1.0 g/mL.
True or False: Water does not change temperature easily."
True or False: Water is highly polar.
True or False: Adding soap to water increases surface tension.
True or False: Evaporation and Vaporization are the same thing."
True or False: Nonpolar substances are NEVER soluble in water."
True or False: Water is an example of an strong IONIC bond..
True or False: The solid phase of water (ice) is more dense than the liquid
phase of water.
The track along which electricity flows is called a:
fuse
circuit
switch
How does increasing the temperature of a system affect the rate of chemical
reactions?
Answer:
Increasing the temperature of a system will increase the rate of a reaction. More particles are moving faster, and have more energy, increasing the overall rate of reaction.
Explanation:
I hope this helps :)
How many liters of O2 would be needed to produce 5.75 moles of K₂O?
Answer:
just 1
Explanation:
Which of the following is a correct statement?
1 :Vacuum is an opaque body
2 :Reflection takes place from the polished smooth surfaces
3 :Moon is a luminous body in the sky
4 :A pin hole camera can take pictures on moving objects
5 :Shadows are always inverted
Answer:
Reflection takes place from the polished smooth surfaces
Explanation:
A vacuum does not refer to an opaque body. An opaque body does not allow light to pass through it while a vacuum is simply empty space without air.
A smooth polished surface often acts as a mirror, it is a good reflector of light.
The moon is a non luminous body in the sky. It merely reflects the light from the sun.
A Pinhole camera can not take pictures of moving objects because it only focuses on any image placed before it.
Shadows are not inverted, the always appear upright.
Explain whether each of the possible reactions listed below will occur. For those that will, predict what the products will be.
Zn(s) + H₂O (l) →
Sn(s) + O2(g) →
Cd(s) + Pb(NO3)2 (aq) →
Cu (s) + HCl(aq) →
Answer:
Zn(s) + 2H₂O (l) → Zn(OH)2(aq) + H2(g)
Sn(s) + O2(g) →SnO2(s)
Cd(s) + Pb(NO3)2 (aq) →Cd(NO3)2 (aq) + Pb(s)
Cu (s) + HCl(aq) → can not occur
Explanation:
Metals reacts with liquid water to yield the corresponding metallic hydroxide and hydrogen gas as shown above; Zn(s) + 2H₂O (l) → Zn(OH)2(aq) + H2(g)
Tin reacts with oxygen to yield tin (IV) oxide. This is an oxidation reaction as shown; Sn(s) + O2(g) →SnO2(s)
The reaction between Cd and Pb(NO3)2 is a single replacement reaction. It is possible because Cd is above Pb in the electrochemical series. Hence the reaction occurs thus; Cd(s) + Pb(NO3)2 (aq) →Cd(NO3)2 (aq) + Pb(s)
Copper does not displace hydrogen from dilute acids (such as HCl) since copper is lower than hydrogen in the electrochemical series hence the reaction does not occur.
Help fast !
If I have an unknown quantity of gas at a pressure of 102 kPa, a volume of 31 liters, and a temperature of 87 0C, how many moles of gas do I have?
Answer:
1 mole represents 6.023×1023 particles.
1 mole of iodine atom= 6.023×1023
Given 127.0g of iodine.
no. of iodine atom = 1 mole of iodine
1mole of magnesium = 24g of Mg = 6.023×1023no.of Mg
Given 48g of Mg = 2×6.023×1023
no. of Mg = 2 moles of Mg
1 mole of chlorine atom= 6.023× 1023
no. of chlorine atom = 35.5g of chlorine atom
Given 71g of chlorine atom=2× 6.023× 1023
no. of chlorine atom = 6.023×1023
2 moles of chlorine atom.
Given that 4g of hydrogen atom.
will be equal to 4 × 6.023 × 1023
no. of atoms of hydrogen= 4 moles of hydrogen atom.
Neon in a piston is compressed to a volume of 14L its original volume was 22 L at 11.2 atm find the new pressure in atm
Which shape of eyeglass lens should be placed in front of the eye in order for the image to form on the retina?
A
concave
B
convex
C
flat
D
objective
Answer:
B
convex: for long sightedness
Or
A
concave: for short sightedness
The concave shape of the eyeglass lens should be placed in front of the eye in order for the image to form on the retina. Therefore, option A is correct.
What is retina ?The retina is a layer of photoreceptor cells and glial cells within the eye that captures incoming photons and transmits them as both electrical and chemical signals to the brain, allowing the brain to perceive a visual image.
The retina converts light that enters your eye into electrical signals that your optic nerve transmits to your brain, resulting in the images you see. It's an important part of your vision. The retina is the layer at the back of your eye.
Placing concave lenses in front of a nearsighted eye reduces light refraction and increases focal length, allowing the image to form on the retina.
A concave lens, which diverges light rays before they enter the eye, allows the myopic eye to focus the image of a distant object on the retina.
Thus, option A is correct.
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Pb(NO3)2(aq)+2KCI(aq)------- PbCl2(s)+2KNO2 (aq). how many grams of PbCl2 solution will react with a 0.46L of a 0.101m KCI solution
Answer:
6.46g of PbCl2 are produced
Explanation:
The PbCl2 will not react, is a product of the reaction. The question must be say how many grams of PbCl2 will be produced
Based on the chemical reaction:
Pb(NO3)2(aq)+2KCI(aq) → PbCl2(s)+2KNO2 (aq)
1 mole of PbCl2 is produced when 2 moles of KCl are reacting.
To solve this question we must find the moles of KCl that will react. With these moles we can find the moles of PbCl2 and the grams produced using its molar mass:
Moles KCl:
0.46L * (0.101moles / L) = 0.04646 moles KCl
Moles PbCl2:
0.04646 moles KCl * (1mol PbCl2 / 2mol KCl) =
0.02323 moles of PbCl2 are produced
Mass -Molar mass PbCl2: 278.106g/mol-
0.02323 moles * (278.106g / mol) =
6.46g of PbCl2 are producedhi so can help me with something
0.45g sample of mineral ore is analyzed for chromium and found contain 0.560mg Cr2 O3. Express concentration of Cr2O3 in sample as percent
Answer:
0.124% of Cr2O3 in the sample
Explanation:
A mass percent is expressed as 100 times the ratio of the mass of analyte and the mass of the sample. For this problem, the equation is:
Mass Cr2O3(g) / Mass Mineral(g) * 100
To solve this question we must convert the mass of Cr2O3 to grams and then, compute the value in the equation:
Mass Cr2O3 in g:
0.560mg * (1g / 1000mg) = 5.6x10⁻⁴g Cr2O3
Percent of Cr2O3 is:
5.6x10⁻⁴g Cr2O3 / 0.45g * 100
0.124% of Cr2O3 in the sampleHow is the motion of particles in a book different from the motion of particles in the air around it ? (dont put link)
Answer:
the motion is different.
Explanation:
the the motion is different because the particle in a book is solid particles and solid are packed together so so they can't move freely but while the the particles in the air around it is gas particles and it are packed very loose and can move very easily anywhere like .Example - solid-book , eraser. gas-helium, oxygen.
1. Molarity of 2.6 moles of NaCl in 2.4 L solution of HOH
2. What is the molarity of a 514 mL solution with 0.46 mol of HSO4
3. What is the molarity of a 1000 mL solution with 12.5 mol of NaOH
4. What is the molarity of a solution of 32.5 grams of KCl in 3.5 L of HOH.
5. What is the molarity of a solution with 84.2 g of CuSO4 in 21,612.2 mL of HOH
6. Molarity of 2.2 g of HCl in 61.2 mL of HOH
7. What is the molarity of 241.8 g Fe2O3 in 500 mL of HOH.
All answers need to be rounded to the nearest 0.01
Answer:
Explanation:
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HOW WILL GENETIC MODIFICATION AFFECT OUR SOCIETY AND ENVIRONMENT?
Answer:
“GMOs have helped farmers reduce their environmental footprint by allowing them to use fewer inputs and enabling a shift to reduced tillage. These practices have led to less time spent on a tractor, less fuel used and fewer emissions.
Hope this helps!!!
In the context of this graph, what do the slope and y-intercept mean?
Answer: The slope and y-intercept values indicate characteristics of the relationship between the two variables x and y. The slope indicates the rate of change in y per unit change in x. The y-intercept indicates the y-value when the x-value is 0.
What is required to make a fire? Is it exothermic or endothermic?
Answer:
Combustion as an Exothermic Reaction
Explanation:
When substances burn, they usually give off energy as heat and light. The combustion of wood is an exothermic reaction that releases a lot of energy as heat and light.
Answer:
Exothermic
Explanation:
because exothermic causes fires while endothermic doesn't
Which measurable property of potassium can be used to support this statement: "Matter can be subdivided to the atomic level while retaining its defining characteristics."
A. Temperature
B. Density
C. Mass
D. Volume
Please help me with this!
Answer:
3.01x10^23
Explanation:
In order to determine the amount of molecules, you have to use Avogadro's number which = 6.02x10^23. To calculate this, multiply the number of moles with Avogadro's number to get the above answer.
Hope this helps!
Read the excerpt from A History of Women’s Suffrage by Stanton, Anthony, and Gage.
Another writer asserts that the tyranny of man over woman has its roots, after all, in his nobler feelings; his love, his chivalry, and his desire to protect woman in the barbarous periods of pillage, lust, and war. But wherever the roots may be traced, the results at this hour are equally disastrous to woman. Her best interests and happiness do not seem to have been consulted in the arrangements made for her protection. She has been bought and sold, caressed and crucified at the will and pleasure of her master. But if a chivalrous desire to protect woman has always been the mainspring of man's dominion over her, it should have prompted him to place in her hands the same weapons of defense he has found to be most effective against wrong and oppression.
Which statement paraphrases the authors’ argument?
Throughout history, men have strived to protect women through chivalrous action and guardianship.
Women have always been subservient to men because they have needed protection during war and pillage.
Men have not been successful protecting women because they have not given women the power to protect themselves.
During times of war, men and women rely on one another for defense, and they each have weapons for battle.
Answer:
C
Explanation:
Took the test
In her book A Vindication of the Rights of Women, British author Mary Wollstonecraft advocated that women should be treated with the same respect and decency as men, particularly when it comes to education. Thus, option C is correct.
What Women’s Suffrage by Stanton, Anthony, and Gage?A Vindication of the Rights of Woman (1792), a groundbreaking feminist text, asserts that girls should be given the same privileges as males.
So that they might become outstanding husbands, mothers, and laborers in addition to being educated to be frivolous and inept by the educational system.
Women should be given the same opportunities as men, and women share the same capacity for reasoning at birth. Women should have the same rights to influence, expertise, and power in society as men do.
Therefore, Men have failed in their attempts to safeguard women because they have not given them the means to do so.
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PLEASE HELP ASAP In the past, California has had many droughts. Which part of the water cycle is not active when a drought is occurring?
precipitation
condensation
transpiration
evaporation
?
Answer :D: evaporation
Explanation: cus i am smart
sorry if i am wrong heh
______________Helps the earth continue to go around the sun
Gravity
Entropy
Magnetism
Inertia
Friction
What are the 3 main types of clouds?
Answer:
Cumulus, Cirrus, and Stratus
Explanation:
So Cumulus Clouds are those puffy-shaped clouds, the ones that look the most solid like you could just walk on them. Cirrus are those wispy clouds that are often very high up. And Stratus Clouds are the low clouds that often cover the entire sky.
hope this helps:)
help pls pls pls I really need this answer
Answer:
I never did this but i think its d 37.5٪ lmk if i got it right pls and srry if i didnt
In a nuclear power plant, what is the purpose of the cooling tower?
cools down the electric generator
reduces heat pollution to the environment
pumps cool water into the reactor
Answer:
reduces heat pollution to the environment
which elements are out of order in terms of atomic mass. co,Ni or Li,be or I,xe
Answer:
The pair co,Ni is out of order in terms of atomic mass
Explanation:
For co,Ni
Atomic mass of Co = 58.9331 u
Atomic mass of Ni = 58.6934
For Li,be
Atomic mass of Li = 6.941 u
Atomic mass of be = 9.012182 u
For I,xe
Atomic mass of I = 126.90447 u
Atomic mass of Xe = 131.293 u
Hence, the pair co,Ni is out of order in terms of atomic mass
2C4H10+13O2-->8CO2+10H2O Using the predicted and balanced equation, How many Liters of CO2 can be produced from 150 grams of C4H10?
Answer: 233 L of [tex]CO_2[/tex] will be produced from 150 grams of [tex]C_4H_{10}[/tex]
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex] [tex]\text{Moles of} C_4H_{10}=\frac{150g}{58g/mol}=2.59moles[/tex]
The balanced chemical equation is:
[tex]2C_4H_{10}+13O_2(g)\rightarrow 8CO_2+10H_2O[/tex]
According to stoichiometry :
2 moles of [tex]C_4H_{10}[/tex] produce = 8 moles of [tex]CO_2[/tex]
Thus 2.59 moles of [tex]C_4H_{10}[/tex] will produce=[tex]\frac{8}{2}\times 2.59=10.4moles[/tex] of [tex]CO_2[/tex]
Volume of [tex]CO_2=moles\times {\text {Molar volume}}=10.4moles\times 22.4mol/L=233L[/tex]
Thus 233 L of [tex]CO_2[/tex] will be produced from 150 grams of [tex]C_4H_{10}[/tex]