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3 years ago

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Which of the following is a source of chemical energy commonly used by humans? A. water flowing in a river B. a bicycle C. a san

dwich D. turning on a lightswitch

1 answer:

ziro4ka [17]3 years ago

7 0

Answer:

Option C sandwich is the correct option

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A ________ is an electric circuit that produces a magnetic field

aksik [14]

I believe it would be D. Electromagnet. It's been a while since I've done this stuff, tho. Hope this helps!!!! :)

5 0

3 years ago

1 lb of CO2 occupies 0.6 ft^3 at a pressure of 200 psi. Determine the temperature of the system.

Anarel [89]

<u>Answer:</u> The temperature of the system is 273 K

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of carbon dioxide = 1 lb = 453.6 g (Conversion factor: 1 lb = 453.6 g)

Molar mass of carbon dioxide = 44 g/mol

Putting values in above equation, we get:

$\text{Moles of carbon dioxide}=\frac{453.6g}{44g/mol}=10.31mol$

To calculate the temperature of gas, we use the equation given by ideal gas equation:

PV = nRT

where,

P = Pressure of carbon dioxide = 200 psia = 13.6 atm (Conversion factor: 1 psia = 0.068 atm)

V = Volume of carbon dioxide = $0.6ft^3=16.992L$ (Conversion factor: $1ft^3=28.32L$ )

n = number of moles of carbon dioxide = 10.31 mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the system = ?

Putting values in above equation, we get:

$13.6atm\times 16.992L=10.31mol\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times T\\\\T=273K$

Hence, the temperature of the system is 273 K

8 0

3 years ago

An ionic bond can be formed when one or more electrons are 1) equally shared by two atoms 2) unequally shared by two atoms 3) tr

Lyrx [107]

Answer:

4) transferred from the valence shell of one atom to the valence shell of another atom

Explanation:

Electrons are located outside of the nucleus which contains the protons and the neutrons.

For bonds to form, valence electrons located in the outermost shell electrons are involved. These are the valence electrons. These outer shell electrons can be shared or transferred between two combining atoms to form stable atoms.

In ionic bonds, the electrons are transferred from one specie to another. The atom that loses the electrons becomes positively charged and the receiving atom becomes negatively charged. This is the crux of ionic bonds.

6 0

3 years ago

Which statement is true about SO4 2− ?

Nonamiya [84]

It is a poly atomic anion because it has more than one atom and a negative charge

4 0

3 years ago

Read 2 more answers

If an atom has three shell and number of valence electrons are two. Is this element metal

cluponka [151]

Answer:

Metal

Element: Calcium

Valency: 2

Explanation:

To find the element, let's use the periodic table. (Look below)

We already went past 3 shells, just need the 2 electrons after it.

Just skip to the 4th row and count 2 to the right

We end up at Calcium.

Calcium is a metal and we're also on the alkaline earth metals column.

Calcium will need to lose 2 electrons to reach stability, so the valency is 2.

3 0

3 years ago