What is the advantage of having valves in the
veins? What is the advantage of having valves in the veins

Answer:

0.385 J/g°C

Explanation:

Using the following formula, the specific heat of an elemental substance can be calculated:

Q = m × c × ∆T

Where;

Q = quantity of heat (J)

m = mass (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

Based on the given information, Q = 1375J, m = 50g, initial temperature = 22.8°C, final temperature = 94.2°C, c =?

Q = m × c × ∆T

1375 = 50 × c × (94.2 - 22.8°C)

1375 = 50 × c × 71.4

1375 = 3570c

c = 1375/3570

c = 0.3851

c = 0.385 J/g°C

Answer:it’s c

Explanation:

Edge 2021

Answer:

Reactants, Activation energy, Energy released by the reaction and Products

Explanation:

This energy profile is that of an exothermic reaction. In an exothermic reaction, heat is liberated to the surrounding. The surrounding becomes hotter than the environment.

The first box to the left is the reactants which signifies the species combining together.

The topmost box is the activation energy which is the energy barrier that must be over come before a reaction takes place.

The box underneath is the energy change. Here, energy is being released.

The right most box is the product of the reaction.

Answer:

The new element will be thorium-226 (²²⁶Th).

Explanation:

The beta decay is given by:

[tex] ^{A}_{Z}X \rightarrow ^{A}_{Z+1}Y + \beta^{-} + \bar{\nu_{e}} [/tex]

Where:

A: is the mass number

Z: is the number of protons  

β⁻: is a beta particle = electron

[tex]\bar{\nu_{e}}[/tex]: is an antineutrino

The neutral atom has 88 electrons, so:

[tex] e^{-} = 88 = Z [/tex]

Hence the element is radium (Ra), it has A = 226.

If Ra undergoes 2 rounds of beta minus decay, we have:

[tex] ^{226}_{88}Ra \rightarrow ^{226}_{89}Ac + \beta^{-} + \bar{\nu_{e}} [/tex]    

[tex] ^{226}_{89}Ac \rightarrow ^{226}_{90}Th + \beta^{-} + \bar{\nu_{e}} [/tex]

Therefore, if a neutral atom with 88 electrons undergoes 2 rounds of beta minus decay the new element will be thorium-226 (²²⁶Th).

I hope it helps you!    

D snails, guppies and plants. The community should be diverse and have lots of biodiversity.

Answer:

to

Explanation:

to

Answer:

V = 10 m³

m = 70 grams

density = ....?

density = m/v

= 70/10

= 7 g/cm³ (B)

Answer:

The loosening of soil and they bind the soil with the help of the roots

Explanation:

Here, we want to know how plants prevent erosion by wind or water.

The way they do this is by binding the soil with their roots such that it will not be easy for the erosion agent to erode the surface.

How they do this is by making sure that the soil

particles are binded together with their roots which helps to keep the particles of the soil intact and not eroded

Answer:

c

Explanation:

Answer:

352kg.m/s

Explanation:

Momentum is the product of mass and velocity. Momentum is a vector quantity. Momentum is the measurement of an object in motion thereby showing how much of the object is in motion. The formula of momentum (p) is given as:

p = mass * velocity

Given that the runner has mass of 55 kg, the momentum at a speed of 6.4 m/s is:

Momentum = mass * velocity = 55 * 6.4 = 352kg.m/s

Answer:352

Explanation:

Answer:

The box exerts a resistance greater than 15 N.

Explanation:

If the student pushed on the box with 15 N and the box didn't more then the box gave a resistance greater than 15 N.

Hope This Helps! (and makes sense!)

Answer:

I really dont know i just guessed :(

Explanation:

Answer:

index of refraction

Explanation:

Answer 1: The two most basic types of bonds are characterized as either ionic or covalent. In ionic bonding, atoms transfer electrons to each other. ... In contrast, atoms with the same electronegativity share electrons in covalent bonds, because neither atom preferentially attracts or repels the shared electrons.

Answer 2 : In ionic bonding, the atoms are bound by attraction of oppositely charged ions, whereas, in covalent bonding, atoms are bound by sharing electrons to attain stable electron configurations.

Answer 3 : Each nitrogen molecule consists of two atoms of nitrogen that are bonded by a triple covalent bond. This is a direct consequence of the fact that each nitrogen atom has 5 valence electrons. Each atom can thus complete its octet by sharing three electrons.

Bark bark Hope this helps :)

Answer:

O_o

Explanation:

Answer:

flows through your viens and moves to your blood vesils

Explanation:

its how blood operates

Answer:

4.97 moles

Explanation:

There are  6.022*10^23 calcium  atoms  in 1 mole of  Ca

2.99*10^24/6.022*10^23

=4.97 moles

Answer:

4.97 mol

Explanation:

Given data:

Number of atoms of Ca = 2.99×10²⁴

Number of moles of Ca = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

2.99×10²⁴  atoms × 1 mol  / 6.022 × 10²³ atoms

0.497×10¹ mol

4.97 mol

Answer:

Lithium sulfide

Answer:

Explanation:

To determine the melting point of the unknown white substances. A sample of each of the unknown can be placed in separate capillary tubes and then placed in an adjustable heat source (for example water bath). A thermometer is then placed in the heat source very close to the tube holding the sample. The temperature of the heat source will be adjusted until the solid substance in the capillary tube starts to melt, the temperature at this point is noted as the melting point.

To determine the conductivity of the white substances, an electrolysis experiment is done. A sample each of the unknown substances is dissolved in water. These aqueous solutions are prepared separately. Two electrodes (positively charged anode and negatively charged cathode) are dipped into each of these solutions and an electric current is passed through these solutions, from an energy source (such as batter), through the electrodes (with the electric current flowing from the anode to the cathode). A voltmeter is then connected to this set-up to determine if electricity is been passed through the individual solutions.

The substance that is the salt will be the white substance that has the higher melting point and conducted electricity in the electrolysis set up; this is because NaCl salt is an ionic compound which has a high melting point and conducts electricity when dissolved in water. While the white substance that had a lower melting point and did not conduct electricity will be the sugar; this is because sugar/sucrose is an organic substance that has a low melting point and does not conduct electricity when dissolved in water.

Answer:

i think that the answer is B

Explanation:

If a student wants to investigate competition between two organisms in an ecosystem the organisms should have same adaptations and use same resources.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

Learn more about ecosystem,here:

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Answer:

wavelength = wave velocity/frequency.

Explanation:

c

 is a constant. It is usually given as

3.00

×

10

8

m/s or

3.00

×

10

10

cm/s rounded to three significant figures.

Wavelength is measured in meters, centimeters, nanometers, etc...).

Frequency has a unit of

1/s

which means

1

cycle per second. It is also given the unit Hertz (Hz) in honor of German physicist Heinrich Hertz who proved the existence of electromagnetic waves.

1

Hz

=

1/s

.

Answer:

A

Explanation:

If there is a whole new solution, then there was definetly a Chemical Change!

~PumpkinSpice1

c is correct

Explanation:

Answer:

The final velocity of the motorcycle is 64.7 m/s

Note: Since the value for the acceleration of the motorcycle is not clear, it is assumed to be 4.55 m/s² in the calculation

Explanation:

Using the equation of motion that contains all the given values in the question: v² = u² + 2as

where v is final velocity; u is initial velocity; a is acceleration; s is horizontal distance

v = ?, u = 0 (since the motorcycle starts from rest), a = 4.55 m/s², s = 460 m

v² = 0² + 2 * 4.55 * 460

v² = 4186

take square root of both sides

v = 64.7 m/s

Therefore, the final velocity of the motorcycle is 64.7 m/s

Answer:

natural gas

Explanation:

your welcomeee

Answer:

The basic metal ones?

Explanation:

...

Answer:

24g

Explanation:

2×12=24

1mole of Mg react with 2 mooe of O2

Answer:

40 Newtons

Explanation:

4.218 is not even close to 40 N.

The 40 N force must be the larger force because 40 has a larger magnitude than the 4.218.

The term magnitude has to do with how large the force is. The larger the force the larger the value that is mentioned.

This implies that the 40 N force must be the larger force because 40 has a larger magnitude than the 4.218.

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Answer:

the element has no subscript because it is only one atom of it

Explanation:

If there isn't a subscript, it's presumed that there is only one atom of that element present.

Subscript is defined as a character that is printed slightly below and to the side of another character, commonly a letter or a number. A subscript is a character that is printed slightly below and to the side of another character, commonly a letter or a number. Chemists frequently employ subscripts in their formulations.

There is no number written if there is just one atom. The number is given as a subscript after the atom if there are multiples of a particular kind of atom. The number on the right side of the symbol indicates how many atoms of that element are contained in the molecule. The atomic number of an element is shown as a subscript on the left-bottom corner of a stand-alone symbol.

Thus, if there isn't a subscript, it's presumed that there is only one atom of that element present.

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Answer: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4

Explanation:

I suggest looking at the electron configuration chart, it has really helped me a lot :)

Answer:

[Ar] 3d10 4s2 4p4

Explanation:

Answer:

Honestly no idea

Explanation:

FOOOOOOOOD

Answer: The products usually weigh more than the reactants.

Explanation:

Answer:

A

Explanation:

i just took the k12 test