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2 years ago

Draw the model of an atom with an atomic number of 7 and a mass number of 15. How many valence electrons are in this atom.

Physics

1 answer:

o-na [289]2 years ago

7 0

Answer:

There are 5 valence electrons

Explanation:

Valence electrons are electrons found in the outermost shell of an atom.

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Which condition is a neuron in when the outside of the neuron has a net positive charge and the inside has a net negative charge

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The condition is a neuron in when the outside of the neuron has a net positive charge and the inside has a net negative charge (due to accumulation of more sodium ions) is C. resting potential. The resting membrane potential of a neuron is approximately -70 mV (mV=millivolt)

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Which of the following is true about elements? A. Atoms of all elements contain the same number of protons, but the number of ne

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D. Atoms of all elements contain protons, but the number of protons is different for every element.

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3 years ago

Force F acts between two charges, q1 and q2, separated by a distance d. If q1 is increased to twice its original value and the d

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Okay, haven't done physics in years, let's see if I remember this.

So Coulomb's Law states that $F = k \frac{Q_1Q_2}{d^2}$ so if we double the charge on $Q_1$ and double the distance to $(2d)$ we plug these into the equation to find

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3 years ago

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A sample of helium gas has a volume of 900. milliliters and a pressure of 2.50 atm at 298 K. What is the new pressure when the t

Sladkaya [172]

Answer:

The new pressure = 5.64 atm.

Explanation:

Using The general gas equation,

P₁V₁/T₁ = P₂V₂/T₂..................... Equation 1

making P₂ the subject of the equation

P₂ = P₁V₁T₂/V₂T₁ ...................... Equation 2

Where P₁ = initial pressure, V₁ = initial Volume, T₁ = Initial temperature, P₂ = final pressure, V₂ = final volume, T₂ = final Temperature.

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Substituting these values into equation 2,

P₂ = (2.5×900×336)/(298×450)

P₂ = 756000/134100

P₂ = 5.64 atm.

Thus the new pressure = 5.64 atm.

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2 years ago

How can you use the movement of molecules to determine when a phase change has occurred?

baherus [9]

Answer:

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Explanation:

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