What happens if someone let's go of the button on an electric door bell

A fluorine ion has 9 protons and a charge of negative one how many electrons are in an ion of fluorine

Ulleksa [173]

-1 charge = the atom has gained one electron

9+1=10

6 0

3 years ago

Find the ratio v/cv/c for an electron in the first excited state (n = 2) of hydrogen.

dezoksy [38]

The answer is 0.365:100.

v/c ratio represents ratio of speed of an electron (v) to the speed of light (c).

How is the speed of an electron calculated?

The speed of an electron (v) is given by Bohr's model as-

$v =\frac{1}{n}\; \frac{e^{2}}{4\pi \varepsilon _{0}}\times \frac{2\pi }{h}$

Now, for the first excited state, n = 2.

e - Charge of electron = $1.6$ × $10^{-19}$ C

h - Plank's constant = $6.6$ × $10^{-34} J.s$

ε₀- permittivity $= 8.85$ × $10^{-12}$ $N^{-1}.C^{2}.m^{-2}$

Put the above data in the formula-

$v =\frac{1}{2}\; \frac{e^{2}}{4\pi \varepsilon _{0}}\times \frac{2\pi }{h} =\frac{1}{4}\times \frac{(1.6\times 10^{-19})^{2}}{8.85\times 10^{-12}\times 6.6\times 10^{-34}}\\ \\ =0.01096\times 10^{8} \\ \\=1.096\times 10^{6}ms^{-1}$

Now, the speed of light, c = $3.0$ × $10^{8}\ m/s$

Thus, the v/c ratio for an electron in the first excited state is calculated as-

$\frac{v}{c} =\frac{1.096* 10^{6}\ m/s }{3.0 *10^{8}\ m/s }$ = $\frac{0.365}{100}$

Hence, the v/c ratio = 0.365:100.

To learn more about the speed of an electron (v), visit:

brainly.com/question/13198566

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6 0

1 year ago

What are the elements in the first period

aliina [53]

Answer:

Explanation:

There are only two elements in the first period: hydrogen and helium. We can explain why there is less elements in the first row in modern theories of atomic structure.

6 0

3 years ago

Read 2 more answers

A warm air is rising as cooler air es in to take its place. what is the name for that?

klasskru [66]

Answer:

convection

hope this helps

have a good day :)

Explanation:

6 0

3 years ago

When the volume of a gas is

Montano1993 [528]

Answer:

$\boxed {\boxed {\sf 232.9 \textdegree C}}$

Explanation:

This question asks us to find the temperature change given a volume change. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula is:

$\frac {V_1}{T_1}= \frac{V_2}{T_2}$

The volume of the gas starts at 250 milliliters and the temperature is 137 °C.

$\frac{250 \ mL}{137 \textdegree C}= \frac{V_2}{T_2}$

The volume of the gas is increased to 425 milliliters, but the temperature is unknown.

$\frac{250 \ mL}{137 \textdegree C}= \frac{425 \ mL}{T_2}$

We are solving for the new temperature, so we must isolate the variable T₂. First, cross multiply. Multiply the first numerator and second denominator, then multiply the first denominator and second numerator.

$250 \ mL * T_2 = 137 \textdegree C * 425 \ mL$