If a person can't accompdate and the glasses is +2.50D. At which distance will the person see cleary

According to the law of conservation of matter, what number must be the same on each side of a chemical equation?

olga2289 [7]

Answer:

4. The number of atoms of each element

Explanation:

Why is 1 wrong?

The number of substances (i.e. number of mols of substances) do not have to be the same. For instance, 2 mol of water reacts with 1 mol of oxygen to form 2 mol of water. Obviously the numer of substances is not conserved. Thus, it isn't a requirement.

Why is 2 wrong?

The number of chemical symbols do not mean anything. They do not tell us anything about the quantity of matter, they only tell us about the elements that are involved in the reaction.

Why is 3 wrong?

Once again, the number of chemical formulas are meaningless.

Why is 4 correct?

The number of atoms are always conserved as atoms cannot be broken or created.

Possible confusion...

The number of atoms are always conserved but the number of molecules may not always be conserved.

Why? As 2 atoms may be a molecule on the reactant side and 4 atoms may become a molecule on the product size, causing the number of molecules to reduce by half, while the number of atoms remain constant.

Hope that makes sense!

7 0

2 years ago

A 18Ω resistance is cut into three equal parts and connected in parallel. Find the equivalent resistance of the combination.

Andrew [12]

Answer:

2Ω

Explanation:

If a 18Ω resistance is cut into three equal parts each of the resistance will be 18Ω/3 = 6Ω

Equivalent ratio in parallel is expressed as:

1/R = 1/6 + 1/6 + 1/6

1/R = 3/6

Cross multiply

3R = 6

R = 6/3

R = 2Ω

Hence the required equivalent resistance is 2Ω

5 0

2 years ago

Two airplanes leave an airport at the same time. The velocity of the first airplane is 730 m/h at a heading of 65.3 ◦ . The velo

yanalaym [24]

Answer:

Plane will 741.6959 m apart after 1.7 hour

Explanation:

We have given time = 1.7 hr

So if we draw the vectors of a 2d graph we see that the difference in angles is = $102^{\circ}-65.3^{\circ}=36.7^{\circ}$

Speed of first plane = 730 m/h

So distance traveled by first plane = 730×1.7 = 1241 m

Speed of second plane = 590 m/hr

So distance traveled by second plane = 590×1.7 = 1003 m

We represent these distances as two sides of the triangle, and the distance between the planes as the side opposing the angle 58.6.

Using the law of cosine, $r^2$ representing the distance between the planes, we see that:

$r^2=1241^2+1003^2-2\times 1003\times 1241cos(36.7)=550112.8295$

r = 741.6959 m

3 0

2 years ago

Help Meeee Please!!!!! This was due so long ago... DO NOT REPORT, THERE IS NO REASON TO REPORT! Assignment: Weathering in Action

zaharov [31]

Answer: Chemical

Explanation: because it is changeing its chemical structure if its wrong sorry .

3 0

2 years ago

A beam of monochromatic light is aimed at a slit of width and forms a diffraction pattern. In which case is the width of the cen

AysviL [449]

When the incident light is yellow the width of the central band greater. Single-wavelength light sources are known as monochromatic lights, where mono stands for one and chroma for color. Monochromatic lights are defined as visible light that falls inside a specific range of wavelengths. It has a wavelength that falls within a constrained wavelength range.

A laser beam is the ideal illustration of monochromatic light. A monochromatic light beam produced by a single atomic transition with a particular single wavelength is what makes up a laser. A color scheme that consists solely of different shades of one color is referred to as monochromatic.

To learn more about monochromatic, click here.

brainly.com/question/23624834

#SPJ4

4 0

1 year ago