All categories

2 years ago

Alan wrote the following examples of changes in substance.

Physics

2 answers:

Anastaziya [24]2 years ago

6 0

Answer:

The correct option is B

Explanation:

A physical change is characterized by the following

no new substance is formed
easily reversible
cannot be represented by a chemical reaction

A chemical change is characterized by the following

new substances are formed
easily reversible
can be represented by a chemical reaction

A camp fire is usually made by burning woods. This process is called combustion, it involves the burning of a substance in oxygen to produce carbon dioxide (CO₂). This is a chemical change because new substance (CO₂) is formed and the ashes formed (after burning) cannot be reversed back to wood.

Plants convert carbon dioxide and water into glucose and oxygen through photosynthesis. This process is also a chemical change because new substances (glucose and oxygen) are formed and the reaction cannot also be easily reversed.

The reaction involved can be represented as

6CO₂ + 6H₂O ⇒ C₆H₁₂O₆ + 6O₂

Yuliya22 [10]2 years ago

5 0

A campfire being lighted and plants converting carbon-dioxide and water into glucose and oxygen are both forms of chemical change.

Therefore, the answer is:

B. Both are examples of chemical change.

You might be interested in

What is the maximum negative displacement a dog could have if it started its motion at +3 m?

raketka [301]

Answer:

- 3 meter

Explanation:

A dog has started motion from +3 meter. ...(Given)

∴ maximum positive distance = + 3 meter

Magnitude of distance = 3

Maximum negative distance = (-) (magnitude of distance)

Maximum negative distance = (-) (3)

Maximum negative distance = -3 meter

Hence, maximum negative distance is -3 meter.

7 0

1 year ago

When you are standing on Earth, orbiting the Sun, and looking at a broken cell phone on the ground, there are gravitational pull

Mandarinka [93]

Answer:

The answer is "Option b, c, and a".

Explanation:

Here that the earth pulls on the phone, as it will accelerate towards Earth when we drop it.

We now understand the effects of gravity:

$F \propto M\\\\F\propto \frac{1}{r^2}\\\\or\\\\F \propto \frac{M}{r^2}\\\\Sun (\frac{M}{r^2}) = \frac{10^{28}}{(10^9)^2} = 10^{10}$

The force of the sun is, therefore, $10^{10}$ times greater and the proper sequence, therefore, option steps are:

b. Pull-on phone from earth

c. Pull-on phone from sun

a. Pull phone from you

5 0

1 year ago

1 Ten (10) ml aqueous solutions of drug A (10% w/v) and drug B (25% w/v) are stored in two identical test tubes under identical

Reil [10]

Answer:

YOUR answer is given below:

Explanation:

3 0

1 year ago

Jin walked 4 km on a straight path to get to the sandwich shop. He traveled 30° south of east.

Molodets [167]

Answer: -2 km

Explanation:

If we imagine Jin's movement to be the hypothenuse of a right triangle, then the southern component of Jin's movement corresponds to the side of the triangle opposite to the angle of 30 degrees. Therefore, the magnitude of this southern component is given by

However, the angle of 30 degrees is south of east: this means that the direction of this southern component is south, and since we generally take north as positive direction, we must add a negative sign, so the correct answer is

-2 km

3 0

2 years ago

Read 2 more answers

Suppose a teenager puts her bicycle on its back and starts the rear wheel spinning from rest to a final angular velocity of 250

shtirl [24]

Answer: a) angular acceleration, a = 5.24rad/s^2

b) time taken for the wheel to stop, ∆t = 0.30s

Explanation:

All shown in the attachment.

3 0

2 years ago