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

which gas would diffuse rapidly at the same temperature and pressure UF6 or CL2

Answers

Answer:

UF6

Explanation:


17. When you hold a soda can in your hand, you possess trillions and trillions of aluminum atoms. In one paragraph, using
your own words, explain how ions of aluminum atoms would generally interact based on their charges, and how that
interaction is overcome through metallic bonding to form the can that you hold.
PLEASE PUT REAL ANSWER OR I WILL REPORT YOU
MARKING BRAINLYEST TO FIRST PERSON

Answers

In the early 1900's, Paul Drüde came up with the "sea of electrons" metallic bonding theory by modeling metals as a mixture of atomic cores (atomic cores = positive nuclei + inner shell of electrons) and valence electrons. Metallic bonds occur among metal atoms. Whereas ionic bonds join metals to non-metals, metallic bonding joins a bulk of metal atoms. A sheet of aluminum foil and a copper wire are both places where you can see metallic bonding in action.

Metals tend to have high melting points and boiling points suggesting strong bonds between the atoms. Even a soft metal like sodium (melting point 97.8°C) melts at a considerably higher temperature than the element (neon) which precedes it in the Periodic Table. Sodium has the electronic structure 1s22s22p63s1. When sodium atoms come together, the electron in the 3s atomic orbital of one sodium atom shares space with the corresponding electron on a neighboring atom to form a molecular orbital - in much the same sort of way that a covalent bond is formed.

The difference, however, is that each sodium atom is being touched by eight other sodium atoms - and the sharing occurs between the central atom and the 3s orbitals on all of the eight other atoms. Each of these eight is in turn being touched by eight sodium atoms, which in turn are touched by eight atoms - and so on and so on, until you have taken in all the atoms in that lump of sodium. All of the 3s orbitals on all of the atoms overlap to give a vast number of molecular orbitals that extend over the whole piece of metal. There have to be huge numbers of molecular orbitals, of course, because any orbital can only hold two electrons.

The electrons can move freely within these molecular orbitals, and so each electron becomes detached from its parent atom. The electrons are said to be delocalized. The metal is held together by the strong forces of attraction between the positive nuclei and the delocalized electrons Hope this helped

define the term pure substance​

Answers

Answer:

Pure substances are substances that are made up of only one kind of particles and has a fixed or constant structure. Pure substances are further classified as elements and compounds. An element is a substance that consists of only one type or kind of atom

Answer:

define the term pure substance​ :

A pure substance does not have to be of a single element or compound, This can either be one single element or one single compound, but every sample of this substance that you examine must contain exactly the same thing with a fixed, definite set of properties

Explanation:

The initial pressure of 0.31 moles of gas in a drum is 742 torr. If gas is added to the drum and the final pressure is 759 torr, how many moles of gas are in the drum? Hint: for this problem, you do not have an equation in the Introduction section, but based on the relationship between pressure and volume, what can you determine about the relationship between pressure and the number of moles?

Answers

Answer:

0.3171 moles

Explanation:

The computation of the number of moles of gas in the drum is shown below;

The ideal gas equation is

PV = nRT

where

P denotes the pressure of the gas

V denotes the volume of the container

n denotes the number of moles of gas

R denotes the Gas constant

T denotes the temperature

Also P proportionate to n

Now the following formula should be used

P_1 ÷ P_2 = n_1 ÷ n_2

742 ÷ 759 = 0.31 ÷  n_2

n_2 = 759 × 0.31 ÷742

= 0.3171 moles

What is the pH of a solution that has a pOH of 5.9

Answers

Answer:

pH = 8.1

Explanation:

Assuming that we are at 25 degrees Celsius, pH + pOH = 14.

We can then plug in the given pOH and solve for pH:

pH + pOH = 14

pH + 5.9 = 14

pH = 14 - 5.9 = 8.1

A basketball inflated to a pressure of 2.25 atm is increased in temperature from 275 K to 317 K.What will be the new pressure, in torr, if the volume remains constant?

Answers

Answer:

[tex]P_2=1971.2torr[/tex]

Explanation:

Hello there!

In this case, by recalling the Gay-Lussac's gas law, as a directly proportional relationship between pressure and temperature, we can write:

[tex]\frac{P_2}{T_2} =\frac{P_1}{T_1}[/tex]

Thus, by solving for the required final pressure, in atmospheres first, we solve for P2 as follows:

[tex]P_2 =\frac{P_1T_2}{T_1}\\\\P_2=\frac{2.25atm*317K}{275K}\\\\P_2=2.59atm[/tex]

Which in Torricelli is:

[tex]P_2=2.59atm *\frac{760torr}{1atm}\\\\P_2=1971.2torr[/tex]

Best regards!

All of the facts about our star the Sun listed below are true EXCEPT which option?
A. the sun is the smallest object in our Solar System.

B. the sun is an average-sized yellow star.

C. the sun is located in an arm of the spiral shaped Milky Way galaxy.

D. the sun appears brighter because it is much closer to Earth than other stars

Answers

Answer:

A

Explanation:

The sun is the smallest object in our solar system

Answer:

A. the sun is the smallest object in our solar system

Explanation:

In 2009, the Hubble Space Telescope discovered the smallest object ever seen in visible light at the time within the Kuiper Belt. The Kuiper Belt Object (KBO) found was a mere 3,200 feet (975 meters) across and was 4.2 billion miles away.

Which of the following is true of all stars? A) they produce energy and radiation B) they have about the same temperature c) they are generally the same size and color D) they produce energy for the same length of time​

Answers

Answer:

A)

Explanation:

All stars produce some type of energy and radiation. But stars vary in temperature, size, color, and the length of energy they produce.

What is the pH of a 4.7 x 10-9 M HCl solution? *

4.67


8.33


11.21


2.93​

Answers

11.21 or 2.93 I think

9. Circle the atom in each pair that has the greater ionization energy.

A) Li or Be
B) Ca or Ba
C) Na or K
D) P or Ar
E) Cl or Si
F) Li or K

Answers

A: BE has more ionization energy than LI

B: CA has more ionization energy than BA.
C: NA has more ionization energy than K

D: AR has more ionization energy than P

E: CI has a more ionization energy than SI
F: LI has more ionization energy than K


If any of these are wrong feel free to correct me in the comments.

A) Be

B) Ca

C) Na

D) Ar

E) Cl

F)  Li

This question simply deals with ionization energy trends across the periodic table or down the group.

Ionization energy is the energy that is needed to remove an electron from its orbital around an atom in such a manner that it will no longer be associated with that same atom.

Now, from studies, it has been found that Ionization energy decreases down a group but it tends to increase as we go from the left to right going across the periodic table.

A) Li(Lithium) and Be(Berrylium) belong to the same period which is period 2 on the periodic table. Berrylium comes after berrylium in that period and as such from the rule earlier, berrylium will have the greater ionization energy.

B) Ca(Calcium) and Ba(Barium) belong to the same group 2 in the periodic table with barium further down the group. Thus, from the trend, Ca(Calcium) will have the greater ionization energy.

C) Na(Sodium) and K(Potassium) belong to the same group 1 in the periodic table with potassium further down the group. Thus, from the trend, Na(Sodium) will have the greater ionization energy.

D) P(Phosphorus) and Ar(Argon) belong to the same period which is period 3 on the periodic table. Argon comes after Phosphorus in that period and as such from the rule earlier, argon will have the greater ionization energy.

E) Cl(Chlorine) and Si(Silicon) belong to the same period which is period 3 on the periodic table. Cl(Chlorine) comes after Si(Silicon) in that period and as such from the rule earlier, Cl(Chlorine) will have the greater ionization energy.

F) Li(Lithium) and K(Potassium) belong to the same group 1 in the periodic table with potassium further down the group. Thus, from the trend,  Li(Lithium) will have the greater ionization energy.

Read more at: brainly.in/question/13610645

What is the percent composition of water found in tin (IV) oxide octahydrate?

Answers

Answer:

tin (IV) oxide octahydrate contains 8 part water

What is the percent composition of water found in tin (IV) oxide octahydrate?

What volume of DI water, in mL, must you use to dissolve 30.0 g of NaOH in order to make a 1.25 M solution? mL (round to whole number)

Answers

Answer:

600mL

Explanation:

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

number of moles = mass/molar mass

Molar mass of NaOH = 23 + 16 + 1

= 40g/mol

mole = 30/40

n of NaOH = 0.75mol

Using Molarity = n/V

V = number of moles ÷ molarity

V = 0.75 ÷ 1.25

V = 0.6L

In milliliters (mL), the volume of NaOH will be 0.6 × 1000

= 600mL

Question :What's oxidation?

Answers

Answer:

The process or result of oxidizing or being oxidized.(Rust)

Explanation:

Pluto

PLEASE PLEASE PLEASE HELP:
An unknown material has 389 J of heat energy added to it. If its specific heat capacity is 0.371 J/g*C and 58 g were affected, what was the temperature increase?

Answers

i know the answer but i really don’t

please help im so bad at science

Answers

a.bond energy

c. endothermic reaction

d. exothermic reaction

f.exothermic

g.endothermic

Blood is made up of red and white blood cells, platelets and ______.






Find the interquartile range

Answers

blood is made up of red and white blood cells, platelets and plasma

A projectile is projected with an initial velocity of 40 m/s at a 45o angle to the horizontal. , calculate the total time travelled.

Answers

Answer:

5.77 s

Explanation:

From the question,

The total time travelled by the projectile = Time of flight (T)

T = 2usinθ/g............ Equation 1

Where T = Time of Flight of the projectile, u = Initial velocity, θ = Angle of projection to the horizontal, g = acceleration due to gravity

Given: u = 40 m/s, θ = 45°

Constant: g = 9.8 m/s²

Substitute these values into equation 1

T = 2(40)sin(45°)/9.8

T = 80sin(45°)/9.8

T = 80×0.7071/9.8

T = 5.77 s

3 of 12
Assessment: Force and Motion CBA
Four students recorded the time it took them to walk to school from their homes as shown in the table
below.
Student
1
2
3
Motion of Four Students
Distance (meters) Time (minutes)
1,100
20
1,026
19
848
16
795
15
4
Which student had the greatest average speed?
Student 1
Student 2
Student 3
Student 4
1
2
3
4
5
6
7
8
9
10
Next

Answers

The answer is 1,026 students hope this helps

HELPPPPP MEEEEE ASAPPP

According to the diagram above, when the north end of the Earth’s axis is tilted toward the sun, explain the suns effect on the North America.

A. North America will experience more indirect rays and shorter days

B. North America will experience more indirect rays and longer days.

C. North America will experience more direct rays and shorter days

D. North America will experience more direct rays and longer days.

Answers

Answer:

the answer is  D

Explanation:

brainliest?

How many Joules are required to heat 40g of water from 13°C to 40°C?
J

Answers

Answer: 1080

Explanation:

you have to subtract 40 from 13 frist then multiply the remins of the temeture with 40 and your answer is 1080

In q = mCΔT, what does C stand for?

Answers

Answer:

The symbol c stands for specific heat and depends on the material and phase. The specific heat is the amount of heat necessary to change the temperature of 1.00 kg of mass by 1.00ºC.

a 1.4g sample of pure gas occupies a volume of 981 mL at 42°C and 117 kPa. Determine the molar mass of the compound.

Answers

Answer:

51 g/mol. Explanation: Whenever you see molar masses in gas law questions, more often than not density will be involved.

At what temperature would the volume of a gas be 0.550 L if it had a volume of 0.432 L at –20.0°C? Be careful! This is not in the correct units for temperature.

Answers

Answer:

49.2°C is the temperature

Explanation:

Based on Charles's law, the absolute temperature of a gas is directly proportional to the volume under constant pressure. The equation is:

V1 / T1 = V2 / T2

Where V is volume and T is absolute temperature of 1, initial state and 2, final state of the gas.

Computing the values of the problem:

V1 = 0.432L

T1 = -20.0°C + 273.15K = 253.15K

V2 = 0.550L

T2 = ?

0.432L / 253.15K = 0.550L / T2

322.3K = T2

322.3K - 273.15 =

49.2°C is the temperature

The pH of a solution is 9.67. Calculate [H+] for the solution

Answers

Answer:

2.14 x 10^-10 M

Explanation:

[H+] = 10^(-pH) = 10^-9.67 = 2.14 x 10^-10 M

What properties can be used to identify puree substances?

Answers

Explanation:

1 it easily won't break down using any chemical

2 it is difficult to extract it using chemical process

mark me please

i need to write a brief paragraph on why this lab is important, please help!! here is the question!
How can the properties of acids and bases be used to classify solutions?

Answers

Answer:

Acids and bases aqueous solutions will conduct electricity because they contain dissolved ions. Therefore acids and bases are electrolytes. strong acids and bases will be electrolytes. weak acids and bases will be weak electrolytes.

Albino trees exist in nature, but they’re rare. These trees contain a gene mutation that causes them to lack chlorophyll, so their leaves are white. In California, albino redwood trees are parasites. They survive off the energy from nearby redwood trees. Why do you think they need to use energy from other trees to survive?

Answers

Answer:

They need to use energy from other tress to survive so that they can do basic functions, like absorbing nutrients from the ground, and growing back leaves. They don't have chlorophyll, so they need that energy to do the functions I mentioned above.

Explanation: Hope this helps!

Answer:

Trees need chlorophyll to make energy. Because albino trees don’t have chlorophyll, they can’t create their own energy. So, they must take energy from other trees to survive.

Explanation:

When mechanical energy is transformed,
A.
potential energy remains unchanged.
B.
heat is given off.
C.
kinetic energy remains unchanged.
D.
friction is encountered.

Answers

Answer:

kinetic energy remains unchanged

I need help answer with right answer

Answers

Answer:

I think it would be D

Explanation:

I NEED HELP ASAP!! What is the difference between the experimental group and a control group?​

Answers

I believe the control group is what doesn't change in the experiment, and the experimental group is what is being tested / receives the treatment :)

Other Questions
A literary critique should always The hot liquid substance that is inside the earth is referred to as lava or magma? A figure was translated 5 units down and 6 to the left and then reflected over the liney = x. The figures are: If a strand has 10% cytosine, what percent will be adenine? Observe: Switch to the Protist sample. Protists are unicellular organisms common in ponds On the MICROSCOPE tab, select the 100x radio button and focus the image.Watch the motion of the protists at 100X and 400X. What structures allow each protist to move?I REALLY NEED HELPP A set of instructions says to subtract 5 from a number n and then double that result, calling the final result p. WhichFunction rule represents this set of instructions?A p = 2(n-5)B. p = 2n-5C. n = 2(p-5)D. n = 2p - 5 37. The sum of two numbers is 86. The larger number is nine less than four times the smaller number. Find both numbers. Please help me, will mark brainliest Please answer the question and hurry!!!! Find the area of the figure.Use 3.14 what is an axis in social 11. A rate written as 80 miles per hour is an example of a(2 points)A.RatioB.Equivalent RatioC.Unit Rate will give you brainliest pls help Was JFK an effective cold warrior or did he worsen the U.S position in the cold war? :) What is the H 2 : H2O molar ratio? Matt walked 1 mile in 15 minutes. At this rate, how many miles would he walk in 2 hours? 4. Think of 5 different muscles in your body and list them. You don't have to use the scientific name. Classify these muscles as either voluntary or involuntary and identify if they are cardiac, smooth or skeletal muscle.Please answer ASAP Hay que entregar la ___ a tiempo Regla Tarea Ayuda Tarde You attended mass, one Sunday , and planned to proceed to the market afterwards to by goods for your family's basic needs. However, during the family, the priest appealed to the people to increase their voluntary contributions so that ' the renovation of the church could be completed. You wanted to give to the project but your money was just enough for the things you planned to buy.. What would you do? Justify your answer. can someone please make this paragaph shorter and paraphrase it? (put it into ur own words I need to understand it better lol) The Renaissance was a fervent period of European cultural, artistic, political and economic rebirth following the Middle Ages. Generally described as taking place from the 14th century to the 17th century, the Renaissance promoted the rediscovery of classical philosophy, literature and art.