How does the heart keep the blood flowing throughout the body?

It contracts and relaxes
It inflates and deflates
It inhales and exhales
It opens and closes

Answers

Answer 1

Answer:

b

Explanation:

Answer 2

Answer:

It contracts and relaxes awnser is a

Explanation:

im from flvs


Related Questions

9
If you wanted to make 250 mL of a 0.01 M solution of CaCl, calculate how many moles of calcium chloride would be
needed. Your response must include both a correct numerical setup and the calculated result. [1]

Answers

Answer:

0.0025moles

Explanation:

Molarity of a solution (M) = number of moles (n) ÷ volume (V)

According to this question, to make 250 mL of a 0.01 M solution of CaCl, the following number of moles is needed:

Volume = 250mL = 250/1000 = 0.250Litres.

Using; molarity = n/V

0.01 = n/0.250

n = 0.0025

n = 2.5 × 10^-3 moles.

why is conventional solar electricity is so expensive to generate??

Answers

Answer:

Most solar cells are made from silicon—the same semiconductor material that is at the heart of computers. The cells are expensive to produce because it takes a great deal of energy to purify the silicon.

ANSWER ASAP Please! How do groups and periods differ? What trend specifically occurs in either?

Answers

A period is a horizontal row of the periodic table. A group is a vertical row of the periodic table. Periodic trends arise from the changes in the atomic structure of the chemical elements within their respective periods (horizontal rows) and groups in the periodic table.

Most large mountains are the result of a(n)?

River
Volcano
Earthquake
Hurricane

Answers

Answer:

C.) Earthquake

Explanation:

Most mountains occur due to the movement of tectonic plates. They slowly push into each other, and the earth's crust rises over time forming mountains.

Earthquakes occur due to the shift of tectonic plates. It sends seismic waves throughout the earth's crust, and causes the ground to shake temporarily.


If we have 0.072 g of FeCl3 then how many moles are there?

Answers

Answer:

~0.0004

Explanation:

[tex]n=\frac{m}{M}[/tex]

n=0.072/(56+(35.5*3))=0.072/162.5~~0.004

The driest desert on Earth is the several years to not receive any rainfall. desert. There it has been recorded for O Atacama Sahara (T) Antartic ( Gobi​

Answers

Answer:

Atacama

Explanation:

Hello, I need help in this part of chemistry, I need the chemical names of the following four:

1) B and F3

2) Se and I2

3) As2 and Se3


ASAP! Please,,, ​

Answers

1- Biron trifluoride
2- selenide
3- arsenic triselenide

I have a Helium party balloon that can hold 3.0 liters of gas. If I blow up this balloon with 0.10 moles of oxygen gas at a pressure of 1.0 atmosphere, what is the temperature of the balloon?

Answers

Answer:

I am not yet sure on my answer

I would not want to give you wrong answers

Sorry

Smoking cigarettes is a lifestyle choice that may lead to cardiovascular disease.
Some people who have never smoked cigarettes still have cardiovascular disease.
Give two other factors that may contribute to the occurrence of cardiovascular
disease.

Answers

Answer:

High blood pressure. High blood pressure (hypertension) is one of the most important risk factors for CVD.

High cholesterol - High-fat diet.

If 3.0 moles of a gas are in a 60.0 liters container at 400.0 K, what is the pressure, in atm, inside
the container?
A.
0.61 atm
B.
16 atm
C.
1.6 atm

Answers

Answer:

C. 1.6 atm

Explanation:

PV = nRT

Solve for P --> P = nRT/V

n = 3.0 mol

R = 0.08206 L atm / mol K

T = 400.0 K

V = 60.0 L

P = (3.0)(0.08206)(400.0) / (60.0) = 1.6 atm

How many grams are in 4.5 x 10^22 molecules of water? please show dimensional analysis

Answers

Answer:

1.1grams

Explanation:

Find moles of water:

4.5x10^22/(6.02x10^23)=0.07mol

Find molar mass of the water

O=16.00g/mol

0.07x 16.00=1.1 grams

Help me pretty please

Answers

Answer:

I'm pretty sure light waves do not require a medium to travel

What are the major parts of the ecosystem

Answers

Answer:

Ecosystems have lots of different living organisms that interact with each other. The living organisms in an ecosystem can be divided into three categories: producers, consumers and decomposers. They are all important parts of an ecosystem. Producers are the green plants.

Explanation:

Hope this helps

At equilibrium A. All reactions have ceased B. Only the forward reaction continues C. Only the reverse reaction continues D. Both the forward and reverse reactions continues

Answers

Answer:

D)both the forward and reverse reactions continue.

Explanation:

Chemical equilibrium can be regarded as state whereby rate of the forward reaction is equal to rate of backward reaction. It should be noted that At equilibrium both the forward and reverse reactions continue.

At a certain temperature 3.24 moles of co2 gas at 2.15atm takes up a volume of 35.28 what is the temperature in celsius

Answers

Answer:

The temperature is 12.35 C.

Explanation:

An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P * V = n * R * T

In this case:

P= 2.15 atmV= 35.28 Ln= 3.24 molesR= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= ?

Replacing:

2.15 atm* 35.28 L= 3.24 moles* 0.082[tex]\frac{atm*L}{mol*K}[/tex] * T

Solving:

[tex]T=\frac{2.15 atm* 35.28 L}{3.24 moles* 0.082\frac{atm*L}{mol*K}}[/tex]

T=285.5 K= 12.35 C (being 273.15 K= 0 C)

The temperature is 12.35 C.

The relation between the moles, volume, temperature, and pressure is given by the ideal gas equation. The temperature of a gas is 12.35 celsius.

What is the ideal gas law?

The ideal gas law is the hypothetical gas law that depicts the relation between pressure, volume, moles of the compound, and the temperature of the gas.

The ideal gas equation is given as,

[tex]\rm PV = nRT[/tex]

Given,

Pressure (P) = 2.15 atm

Volume (V) = 35.28 L

Number of moles (n) = 3.24 mol

Gas constant (R) = 0.082

Temperature (T) = ?

Substituting values in the above equation, the temperature is calculated as:

[tex]\begin{aligned} \rm T &= \rm \dfrac{PV}{nR}\\\\&= \dfrac{2.15\times 35.28}{3.24 \times 0.082}\\\\&= 286.23 \;\rm K\end{aligned}[/tex]

Therefore, 12.35 degrees Celsius is the temperature of the gas.

Learn more about ideal gas law here:

https://brainly.com/question/4406716

6 a What does the sacrificial protection of iron mean?
b Both magnesium and zinc can be used for it. Why?
c But copper will not work. Explain why.

Answers

Explanation:

A-Corrosion

B- Magnesium helps ur body regulates its zinc levels and zinc absorbs into absorbs magnesium more efficiently

Colour of crushed chalk + Iodine solution​

Answers

I guess if you mix them together, the chalk would get less harder.

How do the mass number and atomic change as a particle goes through alpha decay?

Answers

Since an alpha particles is a helium nucleus, it involves the loss of 2 protons and 2 neutrons. As a result, the atom the loses an alpha particle decreases its mass number by four ( 2 protons and 2 neutrons) and decreases it's atomic number by 2 ( it loses two protons).

7. Given the balanced equation:


As a sample of I2(s) sublimes to I2(g), the entropy of the sample

Answers

Gas molecules have more freedom in motion—and gases can be thought of as more “disordered”—than molecules of a solid, which are rigidly held in place. When it comes to phases, the entropy increases as you go from a solid to liquid to gas (the gaseous state having the greatest entropy and the solid state having the least).

So, as a sample of solid iodine sublimes to form gaseous iodine, the entropy of the sample increases.

in what order were the sun and earth created according to both the younger theory and the older theory

Answers

answer: the earth orbits around the sun for 365 while getting older to the young theory.

Answer:

The older theory was that the sun (and other planets) revolved around earth and the new theory is that the earth (and other planets) revolved around the sun.

Explanation:

Convert 812.4 kPa into atm

Answers

Answer:

Explanation:

There are a series of unit used to measure PRESSURE. They include millimetre mercury (mmHg), atmospheric pressure (atm), kilopascal etc. These units of measurement are interconvertible i.e. can be changed from one unit to another.

Based on this question asking to convert

1 kilopascal = 0.00986923atm

A slug travels the length of a log in 2 hours. If the slug's average speed is 1.5 cm / minute how long is the log

Answers

Answer:

The length of the log is 180 cm

Explanation:

From the question given above, the following data were obtained:

Time = 2 hours

Speed = 1.5 cm/min

Distance =?

Next, we shall convert 2 hours to minutes. This can be obtained as follow:

1 h = 60 mins

Therefore,

2 h = 2 × 60

2 h = 120 mins

Finally, we shall determine the Lenght of the log. This can be obtained as follow:

Time = 120 mins

Speed = 1.5 cm/min

Distance =?

Speed = distance / time

15 = distance / 120

Cross multiply

Distance = 1.5 × 120

Distance = 180 cm

Therefore, the length of the log is 180 cm

Answer:

180

Explanation:

The mass of this atom is:
u. 3 mass units
b. 4 mass units
c. 6 mass units
d. 7 mass units
e. 11 mass units

Answers

The answer is going to be c

convert 5.91 x 10^26 molecules h20 to moles

Answers

Answer:

0.432 mol

Explanation:

Divide the given number of molecules by Avogadro's constant. Avogradro's constant is the number of atoms/molecules in a mole of a substance.

Therefore,

2.60

10

23

molecules

6.022

10

23

molecules/mol

=

0.432175 moles

0.432 moles

Explanation:

El mercurio ha sido utilizado como elemento para medir la temperatura porque Es una mezcla. Al aumentar la temperatura se dilata con facilidad. Es un buen conductor del calor. Es un buen conductor de la electricidad.

Answers

Answer:

La respuesta correcta es: Al aumentar la temperatura se dilata con facilidad

Explanation:

El mercurio (Hg) es un elemento metálico que a temperatura ambiente es un líquido. Tiene la propiedad de dilatarse con facilidad al aumentar la temperatura, propiedad que ha sido utilizada en los termómetros de mercurio. En estos termómetros, el mercurio está dentro de un tubo de vidrio graduado con un bulbo para transmitir el calor. Al estar en contacto con un cuerpo más caliente (a mayor temperatura), el mercurio del interior del termómetro se dilata (expande su volumen) y asciende por el tubo indicando la temperatura correspondiente, graduada en el vidrio.

If you start with 13 mole H2O and 50 grams of O2 what is the percent yield of H202 if 100 grams of H202 is actually made?

Answers

Answer:

94.1 %

Explanation:

We firstly determine the equation:

2H₂O + O₂ →  2H₂O₂

2 moles of water react to 1 mol of oxygen in order to produce 2 moles of oxygen peroxide.

We convert the mass of oxygen to moles:50 g . 1mol /32g = 1.56 mol

Certainly oxygen is the limiting reactant.

2 moles of water react to 1 mol of oxygen.

13 moles of water may react to 13/2 = 6.5 moles. (And we only have 1.56)

As we determine the limiting reactant we continue to the products:

1 mol of O₂ can produce 2 moles of H₂O₂

Then 1.56 moles of O₂ will produce (1.56 . 2) = 3.125 moles

We convert the moles to mass: 3.125 mol . 34 g/mol= 106.25 g

That's the 100% yield or it can be called theoretical yield.

Percent yield = (Yield produced / Theoretical yield) . 100

(100g / 106.25 g) . 100 = 94.1 %

1.9x10^23 atoms of sulfur to grams of sulfur

Answers

Answer:

see explanation and punch in the numbers yourself ( will be better for your test)

Explanation:

If you are given atoms you need to divide by Avogadro's number 6.022x10^23

then you will have moles of sulfur-- once you have moles multiply by the molar mass of sulfur to go from moles to grams

mm of sulfur is 32 g/mol

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, the grams of sulfur in  1.9x10²³ atoms of sulfur is 9.92g.

What is mole?

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance.

Given number of atoms= 1.9x10²³atoms

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole =given number of atoms ÷ 6.022×10²³(Avogadro number)

Substituting the values

mole=1.9x10²³÷ 6.022×10²³

mole = 0.31 mole of sulfur

Mole = given mass÷ Molar mass

Molar mass of sulfur=32g/mol

mass of sulfur =0.31 mole ×32g/mol

mass of sulfur=9.92g

Therefore, the grams of sulfur in  1.9x10²³ atoms of sulfur is 9.92g.

To know more about mole, here:

https://brainly.com/question/15209553

#SPJ2

what happens to the rate of a reaction as the reaction progresses

Answers

The rate of a reaction decreases as the reaction progresses.

Of the following elements ____ can form a rare +4 ion *
a) Aluminum
b) Lead
c) Krypton
d) Uranium

Answers

Answer:

d is the answer.........

For the reaction So3 + H2O -> H2SO4, how many grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid

Answers

Answer:

320 grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid.

Explanation:

The balanced reaction is:

SO₃ + H₂O → H₂SO₄

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

SO₃: 1 moleH₂O: 1 moleH₂SO₄: 1 mole

Being the molar mass of each compound:

SO₃: 80 g/moleH₂O: 18 g/moleH₂SO₄: 98 g/mole

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

SO₃: 1 mole* 80 g/mole= 80 gramsH₂O: 1 mole* 18 g/mole= 18 gramsH₂SO₄: 1 mole* 98 g/mole= 98 grams

Then you can apply the following rule of three: if 1 mole of sulfuric acid is produced by the reaction of 80 grams of sulfur trioxide, 4 moles of sulfuric acid is produced from how much mass of sulfur trioxide?

[tex]mass of sulfur trioxide= \frac{4 moles of sulfuric acid* 80 grams of sulfur trioxide}{1 mole of sulfuric acid }[/tex]

mass of sulfur trioxide= 320 grams

320 grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid.

The mass of the required compound is 320 grams

Chemical reactions

Given the chemical equation expressed as:

[tex]SO_3 + H_2O \rightarrow H_2SO_4[/tex]

According to stochiometry, 1 mole of SO3  produces 1 mole of H2SO4, hence the moles of SO3 will also be 4.00moles

Determine the mass of SO3

Mass = mole * molar mass

Mass = 4.0 * [32+3(16)]

Mass = 4.0 * 80

Mass = 320 grams

The mass of the required compound is 320 grams

Learn more on stoichiometry here:  https://brainly.com/question/16060223

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