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3 years ago

What is the mass number of a potassium atom that has 20 neutrons

1 answer:

6 0

<span>The mass of potassium is 39. This is obtained by adding the 19 protons and 20 neutrons found inside the nucleus</span>

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2. State law of conservation of

butalik [34]

Answer:

In collisions between two isolated objects Newton's third law implies that momentum is always conserved. In collisions between two isolated objects momentum is always conserved. Kinetic energy is only conserved in elastic collisions.

Explanation:

3 0

2 years ago

N2 + O2 → 2NO N-N triple bond: 941 kJ/mol O-O double bond: 495 kJ/mol N-O bond: 201 kJ/mol

kiruha [24]

Answer:

$\large \boxed{\text{761 kJ}}$

Explanation:

You calculate the energy required to break all the bonds in the reactants.

Then you subtract the energy needed to break all the bonds in the products.

N₂ + O₂ ⟶ 2NO

N≡N + O=O ⟶ 2O-N=O

Bonds: 2N≡N 1O=O 2N-O + 2N=O

D/kJ·mol⁻¹: 941 495 201 607

$\begin{array}{rcl}\Delta H & = & \sum{D_{\text{reactants}}} - \sum{D_{\text{products}}}\\& = & 2 \times 941 +1 \times 495 - (2 \times 201 + 2\times 607)\\&=& 2377 - 1616\\&=&\textbf{761 kJ}\\\end{array}\\\text{The enthalpy of reaction is $\large \boxed{\textbf{761 kJ}}$}.$

3 0

3 years ago

ou have designed and constructed a solenoid to produce a magnetic field equal in magnitude to that of the Earth (5.0 10-5 T). If

Nikitich [7]

Answer:

$I = 0.0256 A$

Explanation:

Given,

Magnetic field, B = 5 x 10⁻⁵ T

Number of turns, N = 450

length = 29 cm

Current,I = ?

Using formula of magnetic field due to solenoid

$B = \mu_0 NI$

$I = \dfrac{B}{\mu_0N}$

$I = \dfrac{5\times 10^{-5}\times 0.29}{450\times 4\pi \times 10^{-7}}$

$I = 0.0256 A$

Hence, the current obtained is equal to 0.0256 A.

5 0

3 years ago

During a rainy day, as a result of colliding clouds an observer saw lighting and a heard thunder sound. The time between seeing

hodyreva [135]

Answer:

d = 1700 meters

Explanation:

During a rainy day, as a result of colliding clouds an observer saw lighting and a heard thunder sound. The time between seeing the lighting and hearing the sound was 5 second, t = 5 seconds

Speed of sound, v = 340 m/s (say)

Let d is the distance of the colliding cloud from the observer. The distance covered by the object. It is given by :

$d=v\times t$

$d=340\ m/s\times 5\ s$

d = 1700 meters

So, the distance of the colliding cloud from the observer is 1700 meters. Hence, this is the required solution.

8 0

2 years ago

Which describes one event that causes an eclipse?

seraphim [82]

Answer:

earth's shadow covering the moon,thats lunar eclipse

5 0

3 years ago