Why is light a wave?

JJ Thomson's cathode-ray tube experiment showed which of the following?

Flura [38]

The answer would be D

5 0

3 years ago

21 pts. Sodium reacts with oxygen to produce sodium oxide as described by the balanced equation below. If 54.1g of sodium reacts

Aleksandr [31]

First, calculate the amount fo Na2O that should be produced with the given amount of sodium using proper dimensional analysis and the balanced chemical reaction,

theoretical amount of Na2O = (54.1 g of Na)(1 mol Na/23 g Na)(2 mos Na2O/4 mols Na)(62 g Na2O/ 1mol Na2O)

theoretical amount of Na2O = 72.9 g of Na2O

Calculation of percent yield,

% yield = (61.8 g Na2O) / (72.9 g of Na2O) x 100%
% yield = 84.75%

Answer: 84.75%

8 0

3 years ago

A 52.0 mL portion of a 1.20 M solution is diluted to a total volume of 278 mL. A 139 mL portion of that solution is diluted by a

RoseWind [281]

Answer:

$C_3=0.125M$

Explanation:

Hello!

In this case, we can divide the problem in two steps:

1. Dilution to 278 mL: here, the initial concentration and volume are 1.20 M and 52.0 mL respectively, and a final volume of 278 mL, it means that the moles remain the same so we can write:

$V_1C_1=V_2C_2$

So we solve for C2:

$C_2=\frac{C_1V_1}{V_2}=\frac{52.0mL*1.20M}{278mL}\\\\C_2=0.224M$

2. Now, since 111 mL of water is added, we compute the final volume, V3:

$V_3=139+111=250mL$

So, the final concentration of the 139 mL portion is:

$C_3=\frac{139 mL*0.224M}{250mL}\\\\C_3=0.125M$

Best regards!

8 0

3 years ago

Which of the following describes carbon dioxide? O Has polar covalent bonds and is a polar molecule O Has non-polar covalent bon

OLga [1]

Answer: Option "Has polar bonds and is a non-polar molecule" is the correct answer.

Explanation:

A covalent compound is defined as the compound in which there will be sharing of electrons between the combining atoms.

An ionic compound is defined as the compound in which there will be transfer of electrons from one atom to another.

A non-polar covalent compound is defined as the compound in which there will be equal sharing of electrons between the combining atoms.

For example, a chlorine atom has 7 valence electrons.

So, when a chlorine atom chemically combines with another chlorine atom then there occurs equal sharing of electrons.

Hence, molecule $Cl_{2}$ is formed which is non-polar covalent compound in nature with non-polar covalent bond.

A polar covalent bond is defined as the bond in which there will be unequal sharing of electrons between the combining atoms.

For example, a carbon atom has 4 valence electrons and an oxygen atom has 6 valence electrons.

To complete their octet a carbon atom needs 4 more electrons and an oxygen atom needs 2 more electrons.

And, when one carbon and two oxygen atoms chemically combine together then there occurs unequal sharing of electrons.

Hence, a polar covalent compound $CO_{2}$ is formed.

Since, oxygen is more electronegative than carbon atom. Hence, dipoles in the linear carbon dioxide molecules will cancel out each other.

Therefore, a carbon dioxide molecule is non-polar compound that has polar covalent bonds.

Thus, we can conclude that the statement, has polar bonds and is a non-polar molecule, correctly describes carbon dioxide.

8 0

3 years ago

Weathering,erosion,pressing and cementing form what type of rock?

wlad13 [49]

Sedimentary Rock because weathering and erosion breaks down the rock. Then, while the rock is being pressed and cemented, its forms sediments.

6 0

3 years ago

Why is light a wave?​

Why is light a wave?