Which of the following is an example of an electromagnetic wave?

Seismic wave

Radio wave

Water wave

Sound wave?

Answer:

f = 0.94 ×10²⁴  Hz

Explanation:

Given data:

Frequency of light = ?

Wavelength of light = 3.2 ×10⁻¹⁶ m

Solution:

Formula:

Speed of light = wavelength × frequency

c = λ × f

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s  = f × 3.2 ×10⁻¹⁶ m

f  =  3×10⁸ m/s   / 3.2 ×10⁻¹⁶ m

f  = 0.94 ×10²⁴ s⁻¹

f = 0.94 ×10²⁴  Hz (Hz = s⁻¹)

Answer:

2.No. because in an open system, gas will blow up & so, if it's measured, it won't have the equal amount of the reactant. But, if you arrange this reaction in a closed system, then it will be the same.

3.2SiO2+4Cl2= 2SiCl4+O2

Explanation:

Answer:

Its has a lower density. Think about it, a ship in the water is long because if it wasn't it would have a higher density and sink. The ship needs to diperse its weight across the water to make it less dense.

Explanation:

Your welcome! Have a great day!

Answer:

B. 6

Explanation:

Isotope given:

                      ¹⁴₆C

In specie written as this;  

  Superscript  = Mass number

  Subscript  = Atomic number

To find the protons, it is the same as the atomic number;

               Protons  = Atomic number  = 6

Neutrons have no charges;

Neutrons  = Mass number - Atomic number  =

 Neutrons  = 14 - 6  = 8

The number of electrons is the same as the atomic number = 6

Answer:

The unit for mass is the kilogram (Kg).

Explanation:

Hope this helped!! <3 good luckk!!

Answer:

6

Explanation:

ye

Answer:

a

Explanation:

Answer:

D

Explanation:

Answer:

90 Minutes

Explanation:

Original concentration = 120 mg

Half life = 30 minutes

Minimum level = 15 mg

Basically, we are to calculate the time it would take to drop from 120 mg to 15 mg.

The half life of a substance is the time it takes for the original concentration of a substance to drop to half it's starting concentration.

First Half life:

Starting concentration = 120mg

Concentration after half life = 120 / 2 = 60 mg

Second Half life;

Starting concentration = 60 mg

Concentration after half life = 60 / 2 = 30 mg

Third Half life;

Starting concentration = 30 mg

Concentration after half life = 30 / 2 = 15 mg

We have reached the minimum 15 mg level. This means it took three half lives to get there.

Total time taken = No of Half lives * Half life duration = 3 * 30 mins = 90 Minutes

Answer:

784.4kg

Explanation:

Given parameters:

Mass of Mg  = 200kg

Unknown:

Mass of MgCl₂  = ?

Solution:

  The reaction equation is given as:

            Mg  +  Cl₂ →   MgCl₂

Find the number of moles of the given specie;

  Number of moles of Mg = [tex]\frac{mass}{molar mass}[/tex]   = [tex]\frac{200000}{24.3}[/tex]   = 8230.5mole

So;

   1 mole of Mg will produce 1 mole of MgCl₂

   8230.5mole of Mg will produce 8230.5mole of MgCl₂

Mass of MgCl₂   = number of moles x molar mass

                    Molar mass of MgCl₂  = 24.3 + 2(35.5) = 95.3g/mol

 Mass of MgCl₂   = 8230.5mole x  95.3g/mol  = 784.4kg

Answer:

B.9

Explanation:

Answer:

1280L

Explanation:

Given parameters:

Initial pressure  = 0.727atm

Temperature  = 26.9°C

Initial volume  = 726mL  = 0.726L

New pressure  = 0.412atm

Unknown:

New volume of the gas sample  = ?

Solution:

To solve this problem, we apply boyles law;

            P1V1  = P2V2

P and V are pressure and temperature

1 and 2 are initial and new state

             0.727 x 0.726  = 0.412 x V2

                   V2  = 1.28mL  = 1280L

Answer:

Percent yield = 99.6%

Theoretical yield = 25.5 g

Explanation:

Given data:

Mass of copper = 12.5 g

Mass of copper(II) chloride produced = 25.4 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

Cu + Cl₂       →        CuCl₂

Number of moles of copper:

Number of moles = mass/molar mass

Number of moles = 12.5 g / 63.5 g/mol

Number of moles = 0.19 mol

Now we will compare the moles of copper and copper chloride.

                  Cu          :           CuCl₂

                     1           :               1

                  0.19        :           0.19

Mass of CuCl₂: Theoretical yield

Mass = number of moles × molar mass

Mass = 0.19 mol × 134.45 g/mol

Mass = 25.5 g

Percent yield:

Percent yield = (actual yield / theoretical yield )×100

Percent yield  = ( 25.4 g/ 25.5 g) ×100

Percent yield = 99.6%

Answer: [tex]Hg_2^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+2Cl^-(aq)\rightarrow Hg_2Cl_2(s)+2Na^+(aq)+2NO_3^-(aq)[/tex]

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.  

A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.  

The balanced chemical equation is:

[tex]Hg_2(NO_3)_2(aq)+2NaCl(aq)\rightarrow Hg_2Cl_2(s)+2NaNO_3(aq)[/tex]

The complete ionic equation will be :

[tex]Hg_2^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+2Cl^-(aq)\rightarrow Hg_2Cl_2(s)+2Na^+(aq)+2NO_3^-(aq)[/tex]

Answer:

45.9m

Explanation:

Given parameters:

Mass of the ball  = 1kg

Initial velocity  = 30m/s

Unknown:

Height the ball will travel  = ?

Solution:

At the maximum height, the final velocity of the ball  will be 0;

  Using ;

   V²   = U²   - 2gh

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

h is the height

     0² = 30²   - (2 x 9.8 x h)

    0 = 900 - 19.6h

      h  = 45.9m

Answer: [tex]KClO_3[/tex] is the limiting reactant in the given reaction.

Explanation:

Limiting reagent is defined as the chemical specie which gets totally consumed in the reaction and the formation of product is dependent on this reagent.

We are given:

Moles of [tex]P_4[/tex] = 30 moles

Moles of [tex]KClO_3[/tex] = 86 moles

The given chemical equation follows:

[tex]10KCIO_3+3P_4\rightarrow 3P_4O_{10}+10KCI[/tex]

By Stoichiometry of the reaction:

If 10 moles of [tex]KClO_3[/tex] reacts with 3 moles of [tex]P_4[/tex]

Then, 86 moles of [tex]KClO_3[/tex] will react with = [tex]\frac{3}{10}\times 86=25.8moles[/tex] of [tex]P_4[/tex]

As, given amount of [tex]P_4[/tex] is more than the required amount. So, it is considered as an excess reagent.

Therefore, [tex]KClO_3[/tex] is considered as a limiting reactant because it limits the formation of product.

Answer:

The moles present in 60 g of calcium are 1.5 moles.

Answer:

In 60 grams there are 1,5 mols

Explanation:

Answer:

There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.

The correct option which shows the relation between particles of the three substances is 1 mole of aluminum = 1 mole of helium = 1 mole of water.

A particle is a small part of matter.

The term refers to particles of all sizes, ranging from subatomic particles like electrons to visible particles like dust particles floating in sunlight.

The relationship of a number of particles of the substance can be calculated by Avogadro's law

Thus, the correct option is B. 1 mole of aluminum = 1 mole of helium = 1 mole of water

Learn more about particles

https://brainly.com/question/1685421

Answer:

D. the amount of oxygen collected over a period of 12 hours

Explanation:

Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.

According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.

Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.

Answer:

b

Explanation:

Answer:

Liquids

Explanation:because animals like dolphins use sound radiation under water to hear each other

Answer:

D. all of these.

Explanation:

it can travel through solids, liquids, and gasses.

320 g IF₇

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

7.3 × 10²³ molecules IF₇

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of I - 126.90 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of IF₇ - 126.90 + 7(19.00) = 259.9 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

315.056 g IF₇ ≈ 320 g IF₇

Answer: I think that trains move faster then cars! Buttt, The trains are much stronger and bigger, then cars or trucks. Even if they move slowly they can still crush something smaller then them.

Explanation: ( didnt really understand the question, but i tried)

Answer:

2NaCl(l) => 2Na(s) + Cl₂(g)

Explanation:

Electrolysis of melt NaCl to form sodium (Na) metal and chlorine (Cl₂) gas.

This is a class of reaction called 'Decomposition Rxns'. For what it's worth, there are 6 distinct compound types that undergo breakdown by decomposition. The acronym C O A C H E can help remember them.

C - Carbonates => CaCO₃(s) => CaO + CO₂

O - Oxides of Metals => 2Fe₂O₃(s) => 4Fe°(s) + 3O₂(g)

A - Acids (Oxoacids) => H₂CO₃(aq) => CO₂(g) + H₂O(l)

C - Chlorates, Bromates & Iodates => 2KClO₃(s) => 2KCl(s) + 3O₂(g)

H - Hydroxides => Ca(OH)₂(s) => CaO(s) + H₂O(l)

E - Electrolysis => see above electrolysis of NaCl(l)

Answer:

2NaCl(l) => 2Na(s) + Cl₂(g)

Explanation:

Answer:

3

Explanation:

Answer:

The first 5 are exothermic reaction because heat is in product means heat is evolved or given out.

And last no reaction shows that heat is required so last reaction is endothermic reaction.

Explanation:

And heat is evolved in exothermic reaction and heat is absorbed in endo thermic reaction

The reactants in this reaction are sodium and chlorine. Sodium is a soft, silvery-white metal that is highly reactive. Chlorine is a poisonous greenish-yellow gas that has an odor and combines readily with other elements.

This might be the exact question so you might wanna rephrase it but good luck! :)))

A reactant is a substance that undergoes change during a chemical reaction.

A reaction in a chemical experiment is which takes place when there are mixtures between two or more reactants.

There are about four types of reactions which are:

Please note that your question is not complete, therefore, i would give you a general overview to help you.

Some examples of reactants include:

Read more here:

https://brainly.com/question/12056938

Answer:

gas

Explanation:

its either gas or plasma but gas should be it bc liquid and solid are cold

Answer:

Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Answer:

Electromagnetic waves can be split into a range of frequencies. This is known as the electromagnetic spectrum. Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Explanation:

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O