CHEMISTRY MIDDLE SCHOOL

When wood is burned is this a physical or chemical change ?

Answers

Answer 1
Answer: It’s a physical change
Answer 2
Answer:

Answer:

physical

Explanation:

no chemical reaction is occurring

Related Questions

Q: If the average speed of a species of tortoise is 0.36 km/h, what is that speed in cm/s?
The continents do not end at the shoreline. Land forms continue under the sea extending from the continental shelf to the deep ocean floor with a vast variety of life.Choose a list of terms describing land forms found on the ocean floor.A) continental shelf and slope, mid-ocean ridge, rift zone, trench, and the ocean basin B) continental rise and shelf, continent, ridge, canyon, trench, and typhoon C) tectonic plates, continental slope, island, mountain, reef, and the ocean barrier D) continental shelf, ocean basin, mountain ridge, rise, and tidal wave
What does cell division allow ALL multicellular organisms to do? A. reproduce B. repair tissue C. get rid of waste D. produce energy
How many atoms are in 3.20 moles of carbon
How many atoms are in a molecule​

Planets in our solar system do not revolve around the sun in perfect circles. Their orbits are more like ovals that scientists describe as which of the following? A.
revolutionary

B.
rotational

C.
periodical

D.
elliptical

Answers

the answer is elliptical

Answer:

the answer is D

Explanation:

trust me brudda

How many F atoms are there in 0.035 mol CF4

Answers

0.035 mol CF₄ x 4 mols F/ 1 mol CF₄ = 0.14 mols F

0.14 mols F x 6.022x10²³/ 1 mol F= 8.43x10²² atoms

answer: 8.4×10²² atoms of F

maybe try this im not 100% sure though

water in a pan over a radiator evaporates much faster than a water pan in a table ???? i need help ppl

Answers

A pan over the radiator evaporates much faster because it is warmer then a table

A closed container is filled with oxygen. The pressure in the container is 205 kPa
What is the pressure in millimeters of mercury?
Express the pressure numerically in millimeters of mercury.

Answers

Answer:

so pressure in millimeter Hg will be 3016.5 mm Hg

Explanation:

1.)Which of these is a unit of pressure?I. torr
II. mm of Hg
III. L

I only

I and II

II only

II and III

2.)Decreasing the temperature of a gas will __________.

increase the collision rate between gas particles

decrease the collision rate between gas particles

decrease the amount of gas particles in the gas

not affect the collision rate between gas particles

3.)Which of the following pressures is equal to 2.0 atm?

202.6 Pa

202.6 kPa

202,600 kPa

202,600 Pa

4.)What is the correct calculation when converting 4.1 atmospheres to kilopascals?

5.)Decreasing the temperature of a gas decreases the pressure because __________.

the collision rate between gas particles increases

the collision rate between gas particles decreases

the volume of the gas increases

the amount of gas decreases

6.)Which of these is a unit of pressure?
I. kPa
II. torr
III. g

I only

I and II

II only

II and III

7.)How many millimeters of mercury is 2.64 atmospheres equivalent to?

2.01 x 103 mm Hg

3.47 x 10-3 mm Hg

2.88 x 102 mm Hg

2.64 mm Hg

8.)Which of these quantities are equal to 303,900 Pa? ( multiple answers)

303.9 atm

3.0 atm

44.1 psi

1520 mm Hg

Answers

Answer:

Explanation:

1 ) Which of these is a unit of pressure?

Answer:

Option B = I and II

Torr and mmHg both are units of pressure.

While litter (L) is unit of volume.

Torr:

Torr is the measure of pressure produced by one mmHg equal to the 1/760 of standard pressure used to the pressure of vacuum system.

Millimeter mercury mmHg:

It is the manometric pressure unit. It is defined as, the pressure exerted by column of mercury one millimeter high. it is represented by mmHg.

Torr to mmHg conversion:

Both are equal to each other.

1 torr = 1 mmHg

Torr to atm:

Torr is converted into atm by dividing the torr value 760.

mmHg to atm.

mmHg is converted into atm by dividing the torr value 760.

2) Decreasing the temperature of a gas will....

Answer:

option B = Decrease the collision rate between gas particles

when the temperature of gas is increased the average kinetic energy of gas molecules will increased and gas particles moves fast. Thus because of high velocity gas molecules colloid with each other and also with the wall of container. We can say that collision between gas molecules increased by increasing the temperature. The pressure will also goes to increase.

But when the temperature is decreased the kinetic energy of gas molecules goes to decrease and collision will also decreased because of smaller velocity of gas molecules.

3) Which of the following pressure is equal to 2.0 atm.

Answer:

B) 202.6 KPa

In order to convert the pascal to atm we will divide the given value by 101325.

In order to convert the KPa into atm we will divide the value by 101.325.

A) 202.6 pa

202.6/101325

0.002 atm

B) 202.6 KPa

202.6/101.325

2 atm

C) 202,600 kpa

202,600/101.325

1999.5 atm

D) 202,600 Pa

202,600/101325

1.9995 atm

The option b is correct because 202.6 Kpa is equal to 2.0 atm.

4) What is the correct calculation when converting the 4.1 atm to kilopascal?

Answer:

Kilopascal and atm both are units of pressure. They can be converted into one another.

KPa can be converted into atm by dividing the giving KPa value 101.325.

atm can be converted into KPa by multiplying the given atm value with 101.325.

For example:

4.1 atm × 101.325  kpa/ 1 atm

415.432 atm. kpa / 1atm

415.432 kpa

Kpa to atm:

415.432 kpa/101.325  kpa × 1 atm

4.1 × 1 atm

4.1 atm

5) Decreasing the temperature of gas decreases the pressure because

Answer:

option b= The collision rate between gas particles decreased.

when the temperature of gas is increased the average kinetic energy of gas molecules will increased and gas particles moves fast. Thus because of high velocity gas molecules colloid with each other and also with the wall of container. We can say that collision between gas molecules increased by increasing the temperature. The pressure will also goes to increase.

But when the temperature is decreased the kinetic energy of gas molecules goes to decrease and collision will also decreased because of smaller velocity of gas molecules. Thus slow moving particles exerted low pressure.

Temperature and pressure are also directly related to each other. When temperature is high pressure will also high and when temperature is low pressure will also low.

6) Which of these is a unit of pressure?

KPa

Torr

g

Answer:

option B = I and ii

Explanation:

Kpa and torr both are pressure units.

Gram (g) is the unit of mass.

Torr:

Torr is the measure of pressure produced by one mmHg equal to the 1/760 of standard pressure used to the pressure of vacuum system.

Kilopascal:

The kilopascal is the unit of pressure. It is represented by KPa.

it is the pressure generated by 10 g mass of substance on area of 1 cm².

There are 1000 pascal in one kilopasca.

one atm = 101.325 KPa

one atm = 101325 Pa

7) How many mmHg  is 2.64 atmosphere equivalent to ?

2.01 × 10³ mmHg

3.47 × 10⁻³ mmHg

2.88 × 10² mmHg

2.64 mmHg

Answer:

A) 2.0× 10³ mmHg

Explanation:

Millimeter mercury mmHg:

It is the manometric pressure unit. It is defined as, the pressure exerted by column of mercury one millimeter high. it is represented by mmHg.

mmHg to atm.

mmHg is converted into atm by dividing the torr value 760.

atm to mmHg

atm is converted into mmHg by multiplying the given value with 760.

2.64 atm × 760 mmHg / 1 atm

2006.4 mmHg .atm /1 atm

2.0× 10³ mmHg .atm /1 atm

2.0× 10³ mmHg

8) Which of these quantities are equal to 303900 Pa?

303.9 atm

3.0 atm

44.1 psi

1520 mmHg

Answer:

option b = 3.0 atm

it is almost equal to 303,900 Pa but not exactly. because

3.0 atm = 303975 Pa

Explanation:

A) 1 atm = 101325 Pa

303.9 atm × 101325 Pa / 1 atm

30792667.5 Pa .atm  / 1 atm

30792667.5 Pa

b) 3.0 atm

3.0 atm × 101325 Pa / 1 atm

303975 Pa .atm  / 1 atm

303975 Pa

C) 44.1 Psi

44.1 × 6894.757

304058.8 Pa

D) 1520 mmHg

1520 × 133.322

202650 Pa

How do machines transfer and convert energy

Answers

Energy transformation or energy conversion is the process of changing one form of energy to another. In physics, the term energy describes the capacity to produce certain changes within a system, without regards to limitations in transformation imposed.
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