Ask question

Ask question

All categories

4 years ago

13

Which statements about light are true? Select all the correct answers A.It can travel through empty space B.It has no mass C.It

has moving electrons D.It's made of moving electric and magnetic fields God bless everyone

1 answer:

cestrela7 [59]4 years ago

5 0

Answer:

A. It can travel through empty space

Explanation:

Unlike sound it light can travel at an empty space or vacuum.

Hope it helps <3 and Amen.

You might be interested in

Help me please its urgent

Natalija [7]

Answer:

Calcite

Explanation:

The chart shows that calcite is higher than gypsum, but is lower than apatite. Therefore meaning that it can scratch gypsum But not able to the same to apatite.

7 0

3 years ago

When 1.550 g of liquid hexane (C6H14) undergoes combustion in a bomb calorimeter, the temperature rises from 25.87∘C to 38.13∘C.

AlladinOne [14]

Explanation:

1). The given data is as follows.

$T_{i} = 25.87^{o}C$ , $T_{f} = 38.13^{o}C$

C = 5.73 $kJ/^{o}C$

Hence, calculate the change in enthalpy of the reaction as follows.

$\Delta E_{rxn} = -C \times \Delta T$

= $-5.73 \times (38.13 - 25.87)^{o}C$

= -70.25 KJ

As, number of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{1.55}{(6 \times 12 + 14 \times 1)}$

= 0.018 mol

Therefore, enthalpy of reaction in kJ/mol hexane is as follows.

$\Delta E_{rxn} = \frac{-70.25 KJ}{0.018 mol}$

= $-3.90 \times 10^{3}$ kJ/mol

Thus, we can conclude that $\Delta E_{rxn}$ for the reaction in kJ/mol hexane is $-3.90 \times 10^{3}$ kJ/mol .

2). As we know that,

Number of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{1.55}{(7 \times 12 + 8 \times 1)}$

= 0.017 mol

$\Delta E_{rxn} = \E_{rxn} per mol \times \text{number of moles}$

= $-3.91 \times 10^{3} \times 0.017$

= -65.875 kJ

As, $\Delta E_{rxn} = C \times \Delta T
$

-65.875 kJ = $-C \times (37.57 - 23.12)^{o}C$

C = 4.56 $kJ/^{o}C$

Hence, heat capacity of the bomb calorimeter is 4.56 $kJ/^{o}C$ .

3 0

4 years ago

This body system is where oxygen gas and carbon dioxide gas are exchanged in our body. *

nexus9112 [7]

Answer:

The answer is the respiratory system

Explanation:

The function of the respiratory system is to move two gases. These two gases are called oxygen and carbon dioxide. Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them.

6 0

4 years ago

Read 2 more answers

A solution has a pH = 4.63. What is the [H3O+] concentration?

LUCKY_DIMON [66]

Explanation:

The pH of a solution can you be found by using the formula

$pH = - log [ { H_3O}^{+}]$

Since we are finding the [H3O+] , substitute the value of the pH and find it's antilog

We have

$4.63 = - log[ { H_3O}^{+}] \\ [ { H_3O}^{+}] = {10}^{ - 4.63} \\ \\ = 2.344 \times {10}^{ - 5} mol {dm}^{ - 3}$

Hope this helps you

7 0

3 years ago

Summary If you were a conservation scientist, what would you like most about your job?

hodyreva [135]

Explanation:

A conservationist is someone who advocates and champions the cause to protect the environment and use earth's resource in a sustainable way.

One of the interesting perks of being a conservationist is the ability to preserve pristine nature.

This aspect would most fascinate me.
The joy of having to enact laws and policies that would preserve very vital aspect of the ecosystem would such a great delight.
Also, having to champion the cause of indigenous people in whose voices are not often disseminated is a good catch

6 0

3 years ago