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NikAS [45]
2 years ago
12

Number the events from earliest (1) to most recent (6) to outline the development of the cell theory. Anton van Leeuwenhoek obse

rved small organisms he called “animalcules.” Robert Hooke was the first to use the word “cell.” Matthias Schleiden theorized that plants are made of cells. Theodor Schwann theorized that animals are made of cells. Hans and Zacharias Janssen created the first microscope. Rudolf Virchow theorized that cells come from other pre-existing cels
Chemistry
2 answers:
Ne4ueva [31]2 years ago
4 0
I agree with the answer she provided
adelina 88 [10]2 years ago
3 0

1.Hans and Zacharias Janssen created the first microscope.

2.Robert Hooke was the first to use the word “cell.”

3.Anton van Leeuwenhoek observed small organisms he called “animalcules.”

4.Matthias Schleiden theorized that plants are made of cells.

5.Theodor Schwann theorized that animals are made of cells.

6.Rudolf Virchow theorized that cells come from other pre-existing cells.

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The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and
Ipatiy [6.2K]
The statement above is a limitation of the kinetic molecular theory. Kinetic molecular theory is a theory which is based on the assumption that gases are made up of large number of particles which behave like spherical objects in a state of constant, random motion in space. These particles move in a straight path until they collide with another particle or the wall of the container.
4 0
2 years ago
Read 2 more answers
How much energy is required to melt a 500. gram block of iron? The heat of vaporization is 6090 J/g and the heat of fusion is 24
galben [10]

The mass of iron block is 500 g. The amount of energy required to melt the iron block needs to be calculated. Melting means conversion of solid to liquid thus, heat of fusion is used which is 247 J/g.

From heat of fusion, 247 J of energy is released by melting 1 g of iron block. Thus, the amount of heat released by melting 500 g of iron rod will be:

H= 247 J/g× 500 g=1.23×10^{5}

Hence, option B is correct.

3 0
2 years ago
Read 2 more answers
Activity 7: Crossword Puzzle
Ivenika [448]

Answer:

Across

2. Conduction.

3. Plates

4. Convection

5. Subduction

7. Earthquake

Down

1. Radioactive

6. Radiation

8. Sink

9. Slabpull

The clues are;

Across:

2. air molecules come in contact with warmer molecules

3. crust are made up of puzzle - like landmass called_____

4. rising and falling movement of material in the mantle

5. when tectonic plates push with each other

7. it is the result of movement of earth's plate

Down:

1. elements that play a vital role in Earth's internal heat

6. least important mode of heat transport

8. warm material rise; cool material______

9. heats build up underneath the crust

4 0
1 year ago
HELP! Ethanol has a density of 0.8 g/cm3. a. What is the mass of 225 cm3 of ethanol? b. What is the volume of 75.0 g of ethanol?
IRINA_888 [86]

Answer:

The correct answers are:

a) 180 g

b) 93.7 cm³

Explanation:

The density of a substance is the mass of the substance per unit of volume. So, it is calculated as follows:

density= mass/volume

From the data provided in the problem:

density = 0.8 g/cm³

a) Given: volume= 225 cm³

mass= density x volume = 0.8 g/cm³ x 225 cm³ = 180 g

b) Given: mass= 75.0 g

volume = mass/density = 75.0 g/(0.8 g/cm³)= 93.75 cm³≅ 93.7 cm³

5 0
1 year ago
Complete combustion of a compound containing hydrogen and carbon produced 2.641 g of carbon dioxide and 1.442 grams of water as
klio [65]

  The empirical   formula  of hydrocarbon is C₃H₈

The  molecular formula of hydrocarbon   is C₆H₁₆


<u><em> Empirical  formula  calculation</em></u>

Hydrocarbon  contain  carbon and hydrogen

  Step 1:  find the  mass  carbon (C) in carbon dioxide (CO₂)  and hydrogen (H )  in water

mass of  of element = molar mass  of element/ molar mass molecule x total mass of    molecule

From periodic table the molar mass  of C =12,    for CO₂ = 12+( 16 x2) =44 g/mol,     for H = 1.00 g/mol,    for H₂O = (2 x1)+16 = 18 g/mol

mass of C = 12/44 x 2.641 =0.7203 g

since there are 2 atom  of H in H₂O the molar mass of H = 1 x2 = 2 g/mol

mass of H  is therefore =  2/18 x 1.442 =0.1602 g


Step 2:  find the moles of C and H

moles = mass÷ molar mass

moles of C = 0.7203 g÷ 12 g/mol = 0.060  moles

moles of H  =  0.1602÷ 1 g/mol = 0.1602 moles


Step 3: find the mole ratio  of C and H by dividing  each  mole by smallest mole ( 0.06)

for C = 0.06/0.06 =1

  For H = 0.1602/0.06 =2.67

multiply   by 3  to remove the decimal

For C = 1 x3 =3

For H = 2.67 x3 =8

therefore the empirical formula = C₃H₈


<u><em>The molecular formula calculation</em></u>

[C₃H₈]n  = 88.1 g/mol

[12 x 3)+( 1 x8)]n =88.1 g/mol

44 n = 88.1

divide both side by 44

n=2

therefore [C₃H₈]₂   = C₆H₁₆



7 0
1 year ago
Read 2 more answers
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