The atomic number is the number of protons. So, you can subtract the atomic number from the mass number to find the number of neutrons.
I hope this helps! :)

8 0

3 years ago

The maximum distance at which a highway sign can be read is determined for a sample of young people and a sample of older people

liubo4ka [24]

Answer:

The population mean are the same

Explanation:

Answer:

The population means are the same.

Explanation:

The hypotheses for a difference in two population means are similar to those for a difference difference two population proportions.

At null point, Ha=0

Let the mean population of the young one be u1

Let the mean population of the old one be u2.

Then, the difference between their mean population distance is given as

Ha=u2-u1

Since, Ha is null point, Ha=0

0=u2-u1

u2=u1

This shows that the mean population distance of the old is equal to the mean population distance of the young.

Therefore their mean population distance is the same

Since it is null alternative then, the population mean are the same.

We must sample the population using

1. Samples must be random to remove or minimize bias.

2. Sample must be representative of the populations in question.

8 0

3 years ago

Potassium is a crucial element for the healthy operation of the human

Degger [83]

Answer:

The mass of the Potassium-40 is $m_{40}} = 2.88*10^{-6} kg$

The Dose per year in Sieverts is $Dose_s = 26.4 *10^{-10}$

Explanation:

From the question we are told that

The isotopes of potassium in the body are Potassium-39, Potassium-40, and Potassium- 41

Their abundance is 93.26%, 0.012% and 6.728%

The mass of potassium contained in human body is $m = 3.0 g = \frac{3}{1000} = 0.0003 \ kg$ per kg of the body

The mass of the first body is $m_1 = 80 \ kg$

Now the mass of potassium in this body is mathematically evaluated as

$m_p = m * m_1$

substituting value

$m_p = 80 * 0.0003$

$m_p =0.024 kg$

The amount of Potassium-40 present is mathematically evaluated as

$m_{40}} =$ 0.012% * 0.024

$m_{40}} = \frac{0.012}{100} * 0.024$

$m_{40}} = 2.88*10^{-6} kg$

The dose of energy absorbed per year is mathematically represented as

$Dose = \frac{E}{m_1}$

Where E is the energy absorbed which is given as $E = 1.10 MeV = 1.10 * 10^6 * 1.602*10^{-19}$

Substituting value

$Dose = \frac{ 1.10 * 10^6 * 1.602*10^{-19}}{80}$

$Dose = 22*10^{-10} J/kg$

The Dose in Sieverts is evaluated as

$Dose_s = REB * Dose$

$Dose_s = 1.2 * 22*10^{-10}$

$Dose_s = 26.4 *10^{-10}$

3 0

3 years ago

Which sentence describes an example of sublimation?

k0ka [10]

answer C is the correct one

7 0

3 years ago