Jordan is doing a science fair project on the effect of music on the growth of tomatoes. He has two tomatoe plants,plant A and plant B, that he grows in a window and gives that same amount of water.plant A is exposed to classical music using headphones attached to the soil. Throughout the growth period, Jordan counts the number of tomatoes produced by each plant.What is the control group?
What is the independent variable?
What is the dependent variable?
What should jordan's conclusion be?
Jordan need to repeat this experiment, what should he do differently?

The answer is 18

You add each water amount of loose soil and divide by 3

18 i hope this helps

Answer:

207.50°C

Explanation:

Mass of metal (M1) = 440g

Volume of water = 400mL

Initial temperature of water (T2) = 20°C

Final temperature of the mixture (T3) = 35.80°C

Specific heat capacity of the metal (C1) = 0.3850J/g°C

Specific heat capacity of water = 4.184J/g°C

Density of water = 1g/mL

Temperature of metal (T1) = ?

Heat lost by the metal = Heat gained by the water

Q = MC∇T

Q = heat energy

M = Mass

C = specific heat capacity

∇T = change in temperature

M1C1(T1 - T3) = M2C2(T3 - T2)

M2 = ?

Density = mass / volume

Mass = density * volume

Mass = 1g/mL * 400mL

Mass = 400g

M1C1(T1 - T3) = M2C2(T3 - T2)

400 * 0.3850 (T1 - 35.80) = 400 * 4.184 * (35.80 - 20)

154(T1 - 35.80) = 1673.6 * (15.8)

154T1 - 5513.2 = 26442.88

154T1 = 26442.88 + 5513.2

154T1 = 31956.08

T1 = 31956.08 / 154

T1 = 207.50

The initial temperature of the metal was 207.50°C

Answer:

Mass of phosphoric acid = 6.37 g

Mass of magnesium nitride = 50.5 g

Mass of  iron chloride = 22.71 g

Explanation:

1 = Given data:

Mass of phosphorus = 4 g

Mass of phosphoric oxide = ?

Solution:

4P +  5O₂  →  2P₂O₅

Number of moles of phosphorus = mass / molar mass

Number of moles of phosphorus = 4 g / 31 g/mol

Number of moles of phosphorus = 0.13 mol

Mole ration of phosphorus and phosphoric acid.

                                 P        :         P₂O₅

                                 4        :           2

                               0.13      :          2/4× 0.13 = 0.065 mol

Mass of phosphoric acid:

Mass of phosphoric acid = moles × molar mass

Mass of phosphoric acid = 0.065 mol × 98 g/mol

Mass of phosphoric acid = 6.37 g

2 = Given data:

Mass of magnesium = 36 g

Mass of magnesium nitride = ?

Solution:

3Mg  + N₂   →   Mg₃N₂

Number of moles of magnesium = mass / molar mass

Number of moles of magnesium = 36 g / 24 g/mol

Number of moles of magnesium = 1.5 mol

Mole ration of magnesium and magnesium nitride.

                                 Mg     :        Mg₃N₂

                                 3        :           1

                               1.5        :          1/3× 1.5 = 0.5 mol

Mass of magnesium nitride:

Mass of magnesium nitride = moles × molar mass

Mass of magnesium nitride = 0.5 mol × 101 g/mol

Mass of magnesium nitride = 50.5 g

3 = Given data:

Mass of iron = 8 g

Mass of iron chloride = ?

Solution:

2Fe  + 3Cl₂   →   2FeCl₃

Number of moles of iron = mass / molar mass

Number of moles of iron = 8 g / 55.85 g/mol

Number of moles of iron = 0.14 mol

Mole ration of iron and iron chloride.

                                Fe     :        FeCl₃

                                 2        :           2

                               0.14       :          0.14

Mass of iron chloride:

Mass of  iron chloride = moles × molar mass

Mass of iron chloride = 0.14 mol × 162.2 g/mol

Mass of  iron chloride = 22.71 g