Volume of water displaced = 0.175 L Mass g Density g/cm3 Hardness: = Determine the unknown mineral. Unknown mineral: 7

A transverse wave is traveling from north to south. Which statement could be true for the motion of the wave particles in the me

Agata [3.3K]

<span>C. Their direction of motion is south and north. </span>

7 0

3 years ago

What is the amount of heat energy absorbed when 36 grams of ice at -20oC is melted to water at 0oC?

Ulleksa [173]

Answer:

Q = 1461.6 J

Explanation:

Given data:

Mass of ice = 36 g

Initial temperature = -20°C

Final temperature = 0°C

Amount of heat absorbed = ?

Solution:

specific heat capacity of ice is 2.03 j/g.°C

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = T2 - T1

ΔT = 0°C - (-20°C)

ΔT = 20°C

Q = 36 g ×2.03 j/g.°C×20°C

Q = 1461.6 J

3 0

2 years ago

The diameter of a biscuit is approximately 51 millimeters (mm). An atom of bismuth (Bi) is approximately 320. picometers (pm) in

astraxan [27]

Answer:

1.5e+8 atoms of Bismuth.

Explanation:

We need to calculate the <em>ratio</em> of the diameter of a biscuit respect to the diameter of the atom of bismuth (Bi):

$\\ \frac{diameter\;biscuit}{diameter\;atom(Bi)}$

For this, it is necessary to know the values in meters for any of these diameters:

$\\ 1m = 10^{3}mm = 1e+3mm$

$\\ 1m = 10^{12}pm = 1e+12pm$

Having all this information, we can proceed to calculate the diameters for the biscuit and the atom in meters.

<h3>Diameter of an atom of Bismuth(Bi) in meters</h3>

1 atom of Bismuth = 320pm in diameter.

$\\ 320pm*\frac{1m}{10^{12}pm} = 3.20*10^{-10}m$

<h3>Diameter of a biscuit in meters</h3>

$\\ 51mm*\frac{1}{10^{3}mm} = 51*10^{-3}m = 5.1*10^{-2}m$

<h3>Resulting Ratio</h3>

How many times is the diameter of an atom of Bismuth contained in the diameter of the biscuit? The answer is the ratio described above, that is, the ratio of the diameter of the biscuit respect to the diameter of the atom of Bismuth:

$\\ Ratio_{\frac{biscuit}{atom}}= \frac{5.1*10^{-2}m}{3.20*10^{-10}m}$

$\\ Ratio_{\frac{biscuit}{atom}}= \frac{5.1}{3.20}\frac{10^{-2}}{10^{-10}}\frac{m}{m}$

$\\ Ratio_{\frac{biscuit}{atom}}= 1.5*10^{-2+10}$

$\\ Ratio_{\frac{biscuit}{atom}}= 1.5*10^{8}=1.5e+8$

In other words, there are 1.5e+8 diameters of atoms of Bismuth in the diameter of the biscuit in question or simply, it is needed to put 1.5e+8 atoms of Bismuth to span the diameter of a biscuit in a line.

6 0

3 years ago

The positive sign of the energy difference in a chemical reaction would indicate that ..........

trasher [3.6K]

Answer:

B) the chemicals are gaining energy from the surroundings.

Explanation:

The positive sign of the energy difference in a chemical reaction would indicate that the chemicals are gaining energy from the surroundings. This is what happens in an endothermic reaction.

In an endothermic reaction, heat is absorbed from the surroundings hence the surrounding becomes colder at the end of the changes.

Here the energy change is assigned a positive value.
This is because the heat energy level of the final state is higher than that of the initial state.
So, the difference gives a positive value.

3 0

2 years ago

Given 2Na + Cl2=2NaCl, what is the excess reactant? What is the limiting reactant?

QveST [7]

Answer: The limiting reactant is Na

Explanation:

5 0

3 years ago

Volume of water displaced = 0.175 L Mass g Density g/cm3 Hardness: = Determine the unknown mineral. Unknown mineral: 7​

Volume of water displaced = 0.175 L Mass g Density g/cm3 Hardness: = Determine the unknown mineral. Unknown mineral: 7