An atom of phosphorus has an atomic number of 15 and a mass number of 31. how many protons and neutrons does it contain?

Write a chemical equation of Dr. Jeff’s demonstration using a battery to light steel wool on fire. The battery is used to allow

Elis [28]

Answer:

2Fe(s) + 3O2(g) --------> 2FeO3(s)

Explanation:

According to the question, a battery was used to light the steel wool by bringing the terminals very close together. When the battery came into contact with the steel wool, current was sent out through the thin wire. This caused the iron to heat up quite well.

Iron reacts with oxygen under these conditions as follows;

2Fe(s) + 3O2(g) --------> 2FeO3(s)

This is the chemical reaction that occurs when the steel wool is set on fire.

6 0

3 years ago

If the detector is capturing 3.3×108 photons per second at this wavelength, what is the total energy of the photons detected in

Reil [10]

Answer:

The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J

Explanation:

The energy carried by electromagnetic radiation is displaced by waves. This energy is not continuous, but is transmitted grouped into small "quanta" of energy called photons. The energy (E) carried by electromagnetic radiation can be measured in Joules (J). Frequency (ν or f) is the number of times a wave oscillates in one second and is measured in cycles / second or hertz (Hz). The frequency is directly proportional to the energy carried by a radiation, according to the equation: E = h.f, (where h is the Planck constant = 6.63 · 10⁻³⁴ J / s).

Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. it is expressed in units of length (m). In light and other electromagnetic waves that propagate at the speed of light (c), the frequency would be equal to the speed of light (≈ 3 × 10⁸ m / s) between the wavelength :

$f=\frac{speed of light}{wavelength}$

So:

$E=\frac{h*speed of light}{wavelength}$

In this case, the wavelength is 3.35mm=3.35*10⁻³m and the energy per photon is:

$E=\frac{6.63*10^{-34}*3*10^{8}}{3.35*10^{-3} }$

E=5.93*10⁻²³ $\frac{J}{proton}$

The detector is capturing 3.3*10⁸ photons per second. So, in 1 hour:

$E=5.93*10^{-23} \frac{J}{proton} *3.3*10^{8} \frac{proton}{s} *\frac{60}{1} \frac{s}{minute} *\frac{60}{1} \frac{minute}{hr}$

E=7.04*10⁻¹¹ $\frac{J}{hr}$

The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J

3 0

3 years ago

In methane combustion, the following reaction pair is important: At 1500 K, the equilibrium constant Kp has a value of 0.003691

andre [41]

Explanation:

Let us assume that the value of $K_{r}$ = $2.82 \times 10^{5} \times e^({\frac{-9835}{T}}) m^{6}/mol^{2}s$

Also at 1500 K, $K_{r}$ = $2.82 \times 10^{5} \times e^({\frac{-9835}{1500}}) m^{6}/mol^{2}s$

$K_{r} = 400.613 m^{6}/mol^{2}s$

Relation between $K_{p}$ and $K_{c}$ is as follows.

$K_{p} = K_{c}RT$

Putting the given values into the above formula as follows.

$K_{p} = K_{c}RT$

$0.003691 = K_{c} \times 8.314 \times 1500$

$K_{c} = 2.9 \times 10^{-7}$

Also, $K_{c} = \frac{K_{f}}{K_{r}}$

or, $K_{f} = K_{c} \times K_{r}$

= $2.9 \times 10^{-7} \times 400.613$

= $1.1617 \times 10^{-4} m^{6}/mol^{2}s$

Thus, we can conclude that the value of $K_{f}$ is $1.1617 \times 10^{-4} m^{6}/mol^{2}s$ .

6 0

3 years ago

Which of the following is an important application of hydrogen bonding

Andrews [41]

Hydrogen bonding is important because it is crucial to all life on Earth. Here are three reasons why hydrogen bonding is important. DNA has a double-helix structure because hydrogen bonds hold together the base pairs in the middle. Without hydrogen bonds, DNA would have to exist as a different structure.

6 0

3 years ago

Read 2 more answers

The rules of engagement (roe) working group is often used to _____. (select all that apply.)

Gnesinka [82]

Answer:

proactively develop ROE as well as responding to requests for additional ROE measures

Explanation:

The rules of engagement (roe) working group is a group who's main job is to proactively develop ROE as well as responding to requests for additional ROE measures. Rules of Engagement are a set or rules or directives for military soldiers that define the circumstances, conditions, degree, and manner in which the use of force can be used.

3 0

4 years ago