On one side of the cycle, green plants take in carbon atoms from the air make them part of their_____

A mystery object has a density of .75; will it sink or float?

brilliants [131]

Answer:float

Explanation:

8 0

3 years ago

What quantum number of the hydrogen atom comes closest to giving a 24-nm-diameter electron orbit?

Paraphin [41]

<em>n</em> = 15. A Bohr orbit with <em>n</em> = 15 comes closest to having a 24 nm diameter .

The formula for the radius <em>r</em> of the <em>n</em>th orbital of a hydrogen atom is

where

<em>a</em> = the Bohr radius = 0.0529 nm

We can solve this equation to get

<em>n</em> = √ (<em>r</em>/<em>a</em>)

If <em>d</em> = 24 nm, <em>r</em> = 12 nm.

∴ <em>n</em> = √(12 nm/0.0529 nm) = √227 = 15.1

<em>n</em> must be an integer, so <em>n</em> = 15.

4 0

3 years ago

What masses of sodium chloride, magnesium chloride, sodium sulfate, calcium chloride, potassium chloride, and sodium bicarbonate

andreyandreev [35.5K]

Answer:

NaCl: 184g

MgCl₂: 6.60g

Na₂SO₄: 9.26g

CaCl₂: 1.28g

KCl: 0.70g

NaHCO₃: 0.13g

Explanation:

To convert these concentrations to masses we need to convert molarity to moles and moles to grams using molar mass of each salt:

[CaCl₂] = [Ca²⁺] = 0.0115M

[HCO₃⁻] = [NaHCO₃] = 0.0015M

[SO₄²⁻] = [Na₂SO₄] = 0.0652M

[Mg²⁺] = [MgCl₂] = 0.0693M

[K⁺] = [KCl] = 0.0094M

And using the concentration of Cl⁻:

[Cl⁻] = [NaCl] + 2[MgCl₂] + 2[CaCl₂] + [KCl]

[3.32] = [NaCl] + 2[0.0693] + 2[0.0115] + [0.0094]

[NaCl] = 3.149M

The masses you need are:

<em>NaCl (Molar mass: 58.44g/mol):</em>

3.149mol/L * 1L * (58.44g/mol) =

<em>MgCl₂ (Molar mass: 95.211g/mol):</em>

0.0693mol/L * 1L * (95.211g/mol) =

Na₂SO₄<em> (Molar mass: 142.04g/mol):</em>

0.0652mol/L * 1L * (142.04g/mol) =

CaCl₂<em> (Molar mass: 110.98g/mol):</em>

0.0115mol/L * 1L * (110.98g/mol) =

KCl<em> (Molar mass: 74.55g/mol):</em>

0.0094mol/L * 1L * (74.55g/mol) =

<em>NaHCO₃ (Molar mass: 84g/mol):</em>

0.0015mol/L * 1L * (84g/mol) =

<h3>0.13g NaHCO₃</h3>

7 0

3 years ago

Chemical reactions occur when molecules or atoms collide, the bonds between atoms are broken, and new bonds are formed.

schepotkina [342]

Answer:

A. Decreasing the temperature decreases the kinetic energy of the reactants, and the reaction goes more slowly.

C. Reactants must collide, with proper orientation, with energy greater than or equal to the activation energy for a reaction to occur.

D. Increasing the amount of reactants increases the number of collisions, and the reaction goes faster.

F. The energy of a collision between atoms or molecules must be greater than or equal to the activation energy (Ea) for bonds to be broken.

Explanation:

Decreasing the temperature decreases the kinetic energy of the reactants, so fewer molecules have enough kinetic energy to get over the Eₐ barrier, and the reaction goes more slowly.

Reactants must collide, with proper orientation, with energy greater than or equal to Eₐ for a reaction to occur.

Increasing the concentration of reactants increases the frequency of collisions, so the number of successful collisions increases.

The energy of a collision between atoms or molecules must be greater than or equal to Eₐ for bonds to be broken.

B is wrong. If Eₐ is low, more of the molecules can get over the energy barrier, and the reaction rate is fast.

E is wrong. If the energy of the products is higher than the energy of the reactants, the products must have gained energy. The reaction is endothermic.

G is wrong. Eₐ is the energy difference between the energy of the transition state and that of the reactants.

8 0

3 years ago

How many moles of nitrate are dissolved in water if 6.15 mole strontium nitrate dissolve?

pashok25 [27]

The number of moles of nitrate dissolved in water if 6.15 mole of strontium nitrate is : 12.3 moles

<u>Given data :</u>

Moles of strontium nitrate = 6.15 moles

<h3>Ionization of Strontium Nitrate </h3>

When strontium nitrate ( $Sr(NO_{3} )_{2}$ ) is placed in water it will dissociates into its ions because strontium nitrate is an ionic compound.

Next step : Represent the ionization of strontium nitrate

$Sr ( NO_{3} )_{2} (aq) --- > Sr^{2+} (aq) + 2NO_{3} ^{-} (aq)$

From the Stoichiometry of the chemical reaction

I mole of strontium nitrate = 2 moles of Nitrate ions

6.15 mole of strontium nitrate = 2 * 6.15

= 12.3 moles of Nitrate

Hence we can conclude that The number of moles of nitrate dissolved in water if 6.15 mole of strontium nitrate is : 12.3 moles.

Learn more about Stoichiometry of chemical reaction : brainly.com/question/27058367

3 0

3 years ago

On one side of the cycle, green plants take in carbon atoms from the air make them part of their______