pls help and show work!!!

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.

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.

To learn more about the retina, follow the link;

https://brainly.com/question/13993307

#SPJ6

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

Answer:

the charge of an atom is zero.

Explanation:

i hope this is what you were asking for.

Answer:

Insects belong to the class Insecta, and arachnids to the class Arachnida; both classes fall under the Arthropoda phylum, along with crustaceans (crabs, lobster and shrimp). All arthropods have an exoskeleton and jointed legs. They have segmented bodies and appendages, which are divided into different segments. Arachnids belong to an even larger group of animals called “arthropods” which also include insects and crustaceans (lobster, crabs, shrimp, and barnacles).

Explanation:

Answer:

116.88 g

Explanation:

Step 1: Write the balanced equation for the synthesis of NaCl

Na + 1/2 Cl₂ ⇒ NaCl

Step 2: Calculate the moles corresponding to 45.978 g of Na

The molar mass of Na is 22.990 g/mol.

45.978 g × 1 mol/22.990 g = 1.9999 mol

Step 3: Calculate the number of moles of NaCl formed from 1.9999 moles of Na

The molar ratio of Na to NaCl is 1:1. The moles of NaCl formed are 1/1 × 1.9999 mol  = 1.9999 mol.

Step 4: Calculate the mass corresponding to 1.9999 moles of NaCl

The molar mass of NaCl is 58.443 g/mol.

1.9999 mol × 58.443 g/mol = 116.88 g

Answer:

just 1

Explanation:

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:)

An empirical formula presents the atoms of all the elements with the most simplified whole number ratios. In other words, divide each subscript by their greatest common factor.

The greatest common factor of 2 and 4 is 2.

2/2 = 1

4/2 = 2

So, the empirical formula for tetrachloroethene is CCl₂.

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!!!

Answer:

mass = 17.2 grams

Explanation:

q = mcΔT => m = q/cΔT = 187j / (0.90j/g°C)(35.6°C - 23.5°C) = 17.2g

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.

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.

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.

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]

Answer:

The only intermolecular forces present in the compound Hexane are London dispersion forces which are generally the weakest. Hexane's molecular structure proves that Dipole-Dipole forces wont exist as there aren't very polar bonds in the structure.

Answer:

.084 M

Explanation:

Molar mass of sucrose = 342.3

The formula to find molarity is moles of solute / liters of solution

Since we need to turn grams to moles for this equation we do 104 / 342.3 = 0.304

Now we can use the equation listed above. .304 / 3.6 = 0.084 M

Answer: [tex]6.38\times 10^{23}[/tex] molecules of water are produced.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} Fe(OH)_3=\frac{75.50g}{106.8g/mol}=0.707moles[/tex]

The balanced chemical reaction is:

[tex]2Fe(OH)_3\rightarrow Fe_2O_3+3H_2O[/tex]  

According to stoichiometry :

2 moles of [tex]Fe_2O_3[/tex] produce = 3 moles of [tex]H_2O[/tex]

Thus 0.707 moles of [tex]Fe_2O_3[/tex] will produce=[tex]\frac{3}{2}\times 0.707=1.06moles[/tex]  of [tex]H_2O[/tex]  

According to avogadro's law, 1 mole of every substance contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

Thus 1.06 moles of [tex]H_2O[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 1.06=6.38\times 10^{23}[/tex] molecules

Answer:

6.381 x 10^23

Explanation:

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

Answer: B

Explanation:

Answer:

reduces heat pollution to the environment

Answer:

C

Explanation:

Answer:

A change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid. With that said; in a hydraulic brake system, if the piston in the master cylinder(the part your foot pushes on) is one inch square area and you push with 100 pounds, then 100 pounds per square inch is transmitted to all parts of the hydraulic system. Now if the brake caliper piston(the part that pushes against the brake pad) is 2 square inches then there will be a total of 200 lbs of force being applied by the wheel cylinder, because each square inch has 100 pounds pushing on it. This is basically how cars brake systems are designed in order to reduce the amount of force required by the driver.

Btw if u want to give 67 points u must multiply that by 2 since two people answer and they get half of 67.    Im still happy with my 34 though!

Answer:

the ans is in the picture with the steps  

(hope it helps can i plz have brainlist :D hehe)

Explanation:

The concept Boyles law is used here to determine the final pressure of the gas. Boyle's law was put forward by the Anglo-Irish chemist Robert Boyle in the year 1662. The final pressure of the gas is  7.66 atm.

At constant temperature, the volume of a given mass of gas is inversely proportional to its pressure. It can also be explained as at constant temperature, the product of pressure and volume of a given mass of gas is constant.

A straight line graph is obtained when pressure is plotted against the inverse of the volume.

Mathematically the law can be expressed as:

V∝ 1/P

PV = k (Constant)

Here 'V' is the volume and 'P' is the pressure of the gas.

For two different gases, the equation is given as:

P₁V₁ = P₂V₂

P₂ = P₁V₁ / V₂

1 torr = 0.00131 atm

P₁ = 0.023 atm

0.023 × 50.00  / 0.1500 = 7.66 atm

Thus the final pressure is 7.66 atm.

To know more about Boyles law, visit;

https://brainly.com/question/30367133

#SPJ2

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.

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.

Learn more about Women’s here:

https://brainly.com/question/2975708

#SPJ6

Answer: MgAl2O4 or Spinel (gemstone)

Explanation:

Answer:

A

Explanation: