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3 years ago

The modern-day quantum model of the atom is better than John Dalton’s model because it

1 answer:

7 0

The modern-day quantum model of the atom known as the wave mechanical model depicts that the electron was a three dimensional wave circling the nucleus in a whole number of wavelengths allowing the waveform to repeat itself as a stable standing wave (it can absorb energy form a nearby source which is oscillating at a proper frequency) representing the energy levels of Bohr model.

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Only positive ions have a charge. true or false?

Elis [28]

Answer:

true

Explanation:

5 0

3 years ago

A 110 g copper bowl contains 240 g of water, both at 21.0°C. A very hot 410 g copper cylinder is dropped into the water, causing

vlada-n [284]

Answer:

There is 98.76 kJ energy transfered to the water as heat.

Explanation:

Step 1: Data given

Mass of copper bowl = 110 grams

Mass of water = 240 grams

Temperature of water and copper = 21.0 °C

Mass of the hot copper cylinder = 410 grams

8.6 grams being converted to steam

Final temperature = 100 °C

Step 2: Calculate the energy gained by the water:

Q = m(water)*C(water)*ΔT + m(vapor)*Lw

⇒with mass of water = 0.240 kg

⇒ with C(water) = the heat capacity of water = 4184 J/kg°C

⇒ with ΔT = the change in temperature = T2 - T1 = 100 °C - 21.0 = 79°C

⇒ with mass of vapor = 8.60 grams = 0.0086 kg

⇒ with Lw = The latent heat of vaporization (water to steam) = 22.6 *10^5 J/kg

Q = 0.24kg * 4184 J/kg°C *79°C + 0.0086 kg*22.6*10^5 J/kg

Q = 79328.64 + 19436 = 98764.64 J = 98.76 kJ

There is 98.76 kJ energy transfered to the water as heat.

4 0

3 years ago

Lab Scenario D:

Cloud [144]

Answer:

See explanation

Explanation:

A reaction in which heat and light are produced is a combustion reaction. Combustion is said to have occurred when a substance is burnt in oxygen.

The balanced equation of the reaction is;

4Li(s) + O2(g) ------->2Li2O(s)

This reaction is exothermic because heat was produced. The reaction has a low activation energy as the metal easily burst into flames in oxygen. A catalyst is not needed in this reaction because it has a low activation energy.

According to the law of conservation of mass. Atoms are neither created nor destroyed in a chemical reaction. What this means is that in a chemical reaction, the number of atoms of each element on the left hand side must be the same as the same as the number of atoms of the same element on the right hand side.

3 0

3 years ago

For the reaction: 2 A (g) + B (s)= 2 C(s) + D (g)

jolli1 [7]

Answer:

The value of the equilibrium constant = 5.213

Explanation:

Here $K_p$ (equilibrium constant) is referred to as the partial pressure of product divided by the partial pressure of reactant with each pressure term raised to power that is equal to its stoichiometric coefficient in balanced equation .

As such only gas appear in $K_p$ expression as solids takes a value of 1;

SO ; in the given equation from the question:

2 A (g) + B (s) ----> 2 C(s) + D (g)

$K_p = \dfrac{[D]}{[A]^2}$

$K_p = \dfrac{2.71}{0.721^2}$

$K_p = 5.213$

The value of the equilibrium constant = 5.213

8 0

2 years ago

How many cm 3 are in 0.014 in 3? (1 in = 2.54 cm)

pashok25 [27]

Answer:

0.229 cm³.

Explanation:

The following data were obtained from the question:

Volume (in in³) = 0.014 in³

Volume (in cm³) =?

1 in = 2.54 cm

Next, we shall determine a conversion scale to convert from in³ to cm³. This can be obtained as follow:

1 in = 2.54 cm

Therefore,

1 in³ = 2.54³ cm³

1 in³ = 16.387 cm³

Finally, we shall convert 0.014 in³ to cm³. This can be obtained as follow:

1 in³ = 16.387 cm³

Therefore,

0.014 in³ = 0.014 in³ × 16.387 cm³ / 1 in³

0.014 in³ = 0.229 cm³

Thus, 0.014 in³ is equivalent to 0.229 cm³.

7 0

3 years ago