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3 years ago

We can block light by placing obstacles in its path, but it’s much more difficult to block sound. Why?

2 answers:

vladimir2022 [97]3 years ago

6 0

Sound waves can move through various mediums. Similar to the way we can hear a car horn from outside of a house, the sound waves will, however dampened, still pass through mediums, in this case being the wall of a house.

aalyn [17]3 years ago

6 0

Sound waves can move through various mediums.

You might be interested in

If an element has 3 valence electrons, what charge will likely form on its ion? Hint: It will lose those electrons. What happens

guajiro [1.7K]

Answer:

The answer to your question is: letter A

Explanation:

If an atom lose 3 electrons its charge will be positive, it will be +3

6 0

3 years ago

A 7.5 L cylinder contains 5 moles of gas at a temperature of 274°C. What is its pressure in kiloPascals (kPa)?

AleksAgata [21]

<h3><u>Answer;</u></h3>

= 3032.15 kPa

<h3><u>Explanation;</u></h3>

Using the equation;

PV = nRT , where P is the pressure,. V is the volume, n is the number of moles and T is the temperature and R is the gas constant, 0.08206 L. atm. mol−1.

Volume = 7.5 L, T = 274 +273 = 547 K, N = 5 moles

Therefore;

Pressure = nRT/V

= (5 × 0.08206 × 547)/7.5 L

= 29.925 atm

But; 1 atm = 101325 pascals

Hence; Pressure = 3032150.63 pascals

<u>= 3032.15 kPa</u>

3 0

3 years ago

A sample of argon has a volume of 1.2 L at STP. If the temperature is increased to 21 c and the pressure is lowered to 0.80 atm,

Nuetrik [128]

Answer:

The new volume is 1.62 L

Explanation:

Boyle's law says:

"The volume occupied by a given gas mass at constant temperature is inversely proportional to the pressure." It is expressed mathematically as:

Pressure * Volume = constant

o P * V = k

Charles's law is a law that says that when the amount of gas and pressure are kept constant, the ratio between volume and temperature will always have the same value:

$\frac{V}{T}=k$

Gay-Lussac's law indicates that when there is a constant volume, as the temperature increases, the gas pressure increases. And when the temperature is decreased, the gas pressure decreases. So this law indicates that the quotient between pressure and temperature is constant.

Gay-Lussac's law can be expressed mathematically as follows:

$\frac{P}{T}=k$

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law.

$\frac{P*V}{T}=k$

Having an initial state 1 and a final state 2 it is possible to say that:

$\frac{P1*V1}{T1} =\frac{P2*V2}{T2}$

Standard temperature and pressure (STP) indicate pressure conditions P = 1 atm and temperature T = 0 ° C = 273 ° K. Then:

P1= 1 atm
V1= 1.2 L
T1= 273 °K
P2= 0.80 atm
V2= ?
T2= 21°C= 294 °K

Replacing:

$\frac{1 atm* 1.2 L}{273K} =\frac{0.8 atm*V2}{294K}$

Solving:

$V2=\frac{1 atm*1.2 L}{273 K} *\frac{294 K}{0.8 atm}$

V2= 1.62 L

<u><em>The new volume is 1.62 L</em></u>

8 0

3 years ago

Which trend is observed as the first four elements in group 17 on the periodic table are considered in order of increasing atomi

ExtremeBDS [4]

ANSWER:

The melting and boiling points increase in order of increasing atomic number.

The size of the nucleus increases in order of increasing atomic number.

Ionization energy decreases in order of increasing atomic number.

Electronegativity decreases in order of increasing atomic number.

Electron Affinity decreases in order of increasing atomic number.

The reactivities decrease in order of increasing atomic number.

EXPLANATION:

NAME MELTING POINT BOILING POINT

Fluorine -220 -188

Chlorine -101 -35

Bromine -7.2 58.8

Iodine 114 184

Melting and Boiling points increase as shown above.

NAME COVALENT RADIUS IONIC RADIUS

Fluorine 71 133

Chlorine 99 181

Bromine 114 196

Iodine 133 220

Size increases as shown above.

NAME FIRST IONIZATION ENERGY

Fluorine 1681

Chlorine 1251

Bromine 1140

Iodine 1008

Ionization energy decreases as shown above.

NAME ELECTRONEGATIVITY

Fluorine 4

Chlorine 3

Bromine 2.8

Iodine 2.5

Electronegativity decreases as shown above.

NAME ELECTRON AFFINITY

Fluorine -328.0

Chlorine -349.0

Bromine -324.6

Iodine -295.2

Electron affinity decreases as shown above.

REACTIVITY

The reactivities of the halogens decrease. This is due to the fact that atomic radius increases in proportion with an increase of electronic energy levels. This decreases the pull for valence electrons of other atoms, minimizing reactivity.

4 0

3 years ago

Balance the reaction. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the coefficient is "1.

Ann [662]

2HCL + __ Zn --> ZnCl2 + H2

i think that's right, not exactly sure.

7 0

4 years ago

Read 2 more answers