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3 years ago

Define and explain each trend.

1 answer:

3 0

Atomic radius- a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons.
Electron Affinity-the electron affinityof an atom or molecule is defined as the amount of energy released or spent when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion.
Electronegativity-a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used. Fluorine (the most electronegative element) is assigned a value of 4.0, and values range down to caesium and francium which are the least electronegative at 0.7.
Lonization energy- qualitatively defined as the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation.

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What was the Copernican revolution?

Zolol [24]

The Copernican revolution is about the model of the solar system and was given by a polish astronomer. Option C. The discovery that the universe was expanding.

The Copernican Revolution become the paradigm shift from the Ptolemaic model of the heavens, which described the cosmos as having Earth stationery on the center of the universe, to the heliocentric version with the solar on the center of the solar system.

Copernican Revolution, shift the subject of astronomy from a geocentric understanding of the universe, focused around Earth, to heliocentric knowledge, concentrated across the sun, as articulated by the Polish astronomer Nicolaus Copernicus.

This revolution changed the way of thinking of the solar system. Earlier it was thought that earth is in the center of the solar sysytem,i.e; people believed in the geocentric model, but according to Copernicus the solar system has the sun at the center and the remaining planets revolve around it i.e he believed in a heliocentric model.

Learn more about the Copernican revolution here:-brainly.com/question/11385060

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4 0

2 years ago

There is about 1.0 g of calcium as Ca2+ in 1.0 L of milk. What is the molarity of Ca2+ in milk?

meriva

Explanation:

It is known that molarity is the number of moles present in a liter of solution.

Molarity = $\frac{\text{no. of moles}}{volume}$

Also, number of moles equal mass divided by molar mass. And, molar mass of calcium is 40.07 g/mol.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{1.0 g}{40.07 g/mol}$

= 0.025 mol

Therefore, calculate the molarity as follows.

Molarity = $\frac{\text{no. of moles}}{volume}$

= $\frac{0.025 mol}{1.0 L}$

= 0.025 M

Thus, we can conclude that molarity of $Ca^{2+}$ in milk is 0.025 M.

7 0

3 years ago

What is the molar mass of Mg(NO3)2

ipn [44]

Answer: The molar mass of magnesium nitrate is 148.3148 g/mol.

Explanation:

4 0

3 years ago

Static electricity is produced when _____.

lbvjy [14]

Answer:

Atoms gain or lose electrons

Explanation:

6 0

3 years ago

Reynolds number, for an aorta of 0.9-centimeter diameter, calculate the blood flow in liters per minute when the flow regime in

olga55 [171]

Answer:

Flow in liters per minute is 4 L/min

Explanation:

For this case, we have an aorta of 0.9 cm of diameter (D). Let's suppose an uniform and constant diameter for calculation purposes.

D = (0.9 cm)(1m/100cm)

D = 0.009 m

It is required to calculate the blood flow in liters per minute when the flow regime changes from laminar to turbulent. Laminar flow is usually less than 2500 for Reynolds value, and Turbulent flow when Re is higher than 2500. So, we need to study the phenomenon for

Re = 2500.

Using the definition of Reynolds we can find the velocity average of the blood, and use it to find flow. Where blood density is $\rho$ , aorta diameter is D, average velocity is v and blood viscosity is $\mu$

$Re = \frac{\rho v D}{\mu } \\v = \frac{Re*\mu}{\rho D}$

From data problem, we have Re, D values. As we need blood density and blood viscosity we can find them in medical studies. For example: in this online document: Blood flow analysis of the aortic arch using computational fluid dynamics †

Satoshi Numata, Keiichi Itatani, Keiichi Kanda, Kiyoshi Doi, Sachiko Yamazaki, Kazuki Morimoto, Kaichiro Manabe, Koki Ikemoto, Hitoshi Yaku Author Notes

European Journal of Cardio-Thoracic Surgery, Volume 49, Issue 6, June 2016, Pages 1578–1585, https://doi.org/10.1093/ejcts/ezv459

Published: 20 January 2016

$\rho = 1060 kg/m^3\\\mu = 0.0004 kg/(ms)\\$

$v = \frac{Re*\mu}{\rho D}\\v = \frac{2500 * 0.004 kg/(ms)}{(1060 kg/m3)(0.009 m)}\\v = 1.04 m/s\\$

Average blood velocity is 1.04 m/s. After that, we can calculate the flow (Q) using the flow are (Ao) of aorta.

Q = v*Ao

$Q = (1.4m/s)*(\pi*(0.009m/2)^2)\\Q = 6.67 * 10^-5 \frac{m^3}{s}\\Q = (6.67 * 10^-5 \frac{m^3}{s})(\frac{1000 L}{1 m^3} ) (\frac{60 s}{1 min} )\\Q = 4 L/min$

Finally, the blood flow in liters per minute is 4 L/min when the flow regime in the aorta changes from laminar to turbulent.

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3 years ago