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2 years ago

HALLP ME STUCKKKKK

Chemistry

2 answers:

likoan [24]2 years ago

7 0

Answer:

The average height of the sunflower sprouts at the end of week 3 is 12.0

cm.

The average height of the birch sprouts at the end of week 3 is 7.2

cm.

Explanation:

they showed it on edgu

astra-53 [7]2 years ago

4 0

Answer: Sunflower height-12.0 centimeters

Birch Plant-7.2 centimeters

Explanation:

Its how much they grew.

You might be interested in

How many carbon atoms are contained in 2.8 g of c2h4 ?

MrRa [10]

Answer:

The answer to your question is: 1.205 x 10²³ atoms of Carbon

Explanation:

Data

Carbons atoms contained in 2.8 g C₂ H₄

MW C₂ H₄ = (12 x 2) + (4 x 1) = 24 + 4 = 28 g

28 g of C₂ H₄ ---------------- 24 g of carbon

2.8 g C₂ H₄ ----------------- x

x = (2.8)(24) / (28)

= 2.4 grams of C

1 mol ------------------- 12 g of Carbon

x ------------------- 2.4 g

x = (2.4x 1) / 12 = 0.2 mol

1 mol ----------------- 6.023 x 10 ²³ atoms

0.2 mol -------------- x

x = (0.2 x 6.023 x 10 ²³) / 1

= 1.205 x 10²³ atoms

8 0

2 years ago

Read 2 more answers

Select the correct answer from each drop-down menu.

nataly862011 [7]

The arrow shows that the bond between the chlorine atom and the fluorine atom is nonpolar. The electrons in the bond are pulled more strongly by the fluorine atom, and the chlorine atom is slightly positive.

Explanation:

The bond between Chlorine and fluorine is nonpolar bonding because both of them are sharing an equal number of electrons in the bond. H2, F2, and CL2 are common examples of this.

Chlorine and fluorine are electronegative molecules but Fluorine is above chlorine in the periodic table. Since fluorine is above Chlorine, fluorine has slightly highest electronegative nature compare to fluorine. This is the reason why Fluorine molecules are attracting electrons more than chlorine atoms. This making chlorine atoms slightly positive in Cl and F bonding.

8 0

2 years ago

Read 2 more answers

Express each aqueous concentration in the unit indicated.

MAXImum [283]

Answer:

a. ppb of trichloroethylene = 3 × 10⁶ ppb

b. ppm of Cl₂ = 3.8 ppm

c. Molarity = 0.0002 mol / L

d. Molarity = 0.0007 mol / L

e. For trace amount of concentrations

Explanation:

a. Given data

mass of trichloroethylene = 25 mg

Volume of water = 9.5 L

ppb of trichloroethylene = ?

Solution

As we know that

1 L = 1000 milliliters

9.5 L = 9.5 × 1000

9.5 L = 9500 millileters (ml)

we consider 25 mg = 25 millileters

ppb = (mass of solute / mass of solvent) × 1000,000,000 (1 billion)

ppb of trichloroethylene = (25 ÷ 9500) × 1000,000,000

ppb of trichloroethylene = 0.003 × 1000,000,000

ppb of trichloroethylene = 3 × 10⁶ ppb

B. Given data

Mass of Cl₂ = 38 g

volume of water = 1.00 × 10⁴ L ( 10000 L)

ppm of Cl₂ = ?

Solution

Volume of water in ml = 1 L = 1000 ml

Volume of water in ml = 10000 × 1000

Volume of water in ml = 10000000 ml

we take 38 g = 38 ml

Now we convert it to ppm

ppm = (mass of solute / mass of solvent) × 1000000 (1 million)

ppm of Cl₂ = ( 38 ÷ 10000000 ) × 1000000

ppm of Cl₂ = 0.0000038 × 1000000

ppm of Cl₂ = 3.8 ppm

C. Given data

Concentration of F⁻ ( Fluoride ion) = 2.4 ppm

Molarity = ?

Solution

As we know that 1 ppm = 0.001 g / L

2.4 ppm = 2.4 × 0.001 g/L

2.4 ppm = 0.0024 g/L

Mass of flouride ions = 0.0024 g

Now we find number of moles

moles = mass / molar mass

molar mass of F⁻ = 19 g/mol

moles of F⁻ = 0.0024 g / 19 g/mol

moles of F⁻ = 0.0002 mol

Molarity = mol of solute / liter of solution

Molarity = 0.0002 mol / 1 L

Molarity = 0.0002 mol / L

D. Given data

Concentration of NO₃⁻ ( nitrate ion) = 45 ppm

Molarity = ?

Solution

As we know that 1 ppm = 0.001 g / L

45 ppm = 45 × 0.001 g/L

45 ppm = 0.045 g/L

Mass of nitrate ions = 0.045 g

Now we find number of moles

moles = mass / molar mass

molar mass of NO₃⁻ = 62 g/mol

moles of NO₃⁻ = 0.045 g / 62 g/mol

moles of F⁻ = 0.0007 mol

Molarity = mol of solute / liter of solution

Molarity = 0.0007 mol / 1 L

Molarity = 0.0007 mol / L

E. Reason of expressing concentration in ppm and ppb

Scientist prefer ppm and ppb notations when the concentration difference of solute and solvent are very high.

As water contains contaminants is a very low amount we can say in trace amounts so scientist prefer ppm and ppb rather than molarity.

Example

Arcenic is an under ground water contaminant and its concentration of 10 μg/L is dangerous for health.

Lets change this in to molarity

mass = 10 μg

10 μg = 10 / 1000000

10 μg = 0.00001 g

now find out moles of Arcenic

moles = mass / molar mass

molar mass of arcenic = 75 g/mol

moles = mass / molar mass

moles of arcenic = 0.00001 g / 75 g/mol

moles of arcenic = 0.00000012 mol

Molarity = moles of solute / litres of solution

Molarity = 0.00000012 mol / 1 L

Molarity = 0.00000012 mol/ L

As we can see that in molarity it is a negligible amount so scientists express it in ppm and ppb

7 0

2 years ago

What scientific knowledge was necessary for Kroto, Smalley, and Curl to discover buckyballs? Check all that apply. All matter is

taurus [48]

All matter is made of atoms.

Atoms bond together in certain ways.

Carbon atoms have a specific mass.

8 0

2 years ago

Read 2 more answers

Label each statement with its corresponding type of scientific knowledge. law theory fact hypothesis The melting point of ice is

EleoNora [17]

Answer:

Follows are the solution to this question:

Explanation:

Fact: In this, the ice is melted at 0 ° C.
law: It is used to repeated experiments consistently showed which objects marked to both the contrary attract each law.
Hypothesis: If carbohydrates and nitrogen are combined at 1500 ° C, they interact with one another.
Theory: Protons, nuclei, or ions are made of Atoms. As these molecules could not be seen explicitly, such legal structure several experimental observations.

3 0

2 years ago