help me please !! is it A,B,C, or D ???

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:

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:

flows through your viens and moves to your blood vesils

Explanation:

its how blood operates

Answer:

anime

Explanation:

Answer: The products usually weigh more than the reactants.

Explanation:

Answer:

A

Explanation:

i just took the k12 test

Answer:

The basic metal ones?

Explanation:

...

Answer:

24g

Explanation:

2×12=24

1mole of Mg react with 2 mooe of O2

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:

550 K

Explanation:

Given the following data;

Original Volume, V1 = 20mL

Original Temperature, T1 = 200K

New Temperature, V2 = 55mL

To find new temperature T2, we would use Charles' law.

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles is given by;

[tex] VT = K[/tex]

[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]

Making T2 the subject of formula, we have;

[tex]T_{2} = \frac{V2}{V1} * T_{1}\\[/tex]

Substituting into the equation;

[tex]T_{2} = \frac{55}{20} * 200\\T_{2} = \frac{11000}{20}\\T_{2} = 550K[/tex]

Therefore, the new temperature is 550K.

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:

I want to say its Lonic Bonding.

Explanation:

Ionic bonding is the complete transfer of valence electron(s) between atoms.

Answer:

5730 years

Explanation: for more on radiocarbon dating.) and hence explain why the amount of carbon-14 in the sample decays by half over any period of 5730 years.

Answer: Lithium ( 3),Calcium (20),Copper (29),Strontium (38),Potassium (19),Sodium (11)

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:

CH4

- 4 electron

- 0 electron

- the geometry of Ch4 is tetrahedral

AlF3

- 3 electron

- 0 electron

- the geometry is trigonal planar

CCl4

- 4 electron

- 0 electron

- the geomotry is tetrahedral

SeH2

- 2 electron

- 2 electron

- the geometry is V shape

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:

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!    

Answer: 25 + 27 + 29 = 81

81 divided by 3 = 27

your answer is 27

Explanation: you add them all together then however many numbers there are is how you divide it

Answer:

81 and 27 i think

Explanation:

Answer:

Corona Virus outbreak

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:

D

Explanation:

The one that best represents a compound is answer "D" because you compounds are chemically bonded and are always together.

Answer:

mutualism,commensalism and parasitism

Answer:

mutualism, commensalism, and parasitism

Answer:

I'm gonna say A and B

Explanation:

Not sure though

Hope I helped :)

Answer:it’s c

Explanation:

Edge 2021

Answer:

V = 10 m³

m = 70 grams

density = ....?

density = m/v

= 70/10

= 7 g/cm³ (B)

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.

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Answer:

Air Temp 77F Dew-point 19F

Explanation:

Quiz

The dew point can be described as the temperature required by the air to be cooled. The driest air will have a higher dew point, therefore, at an air temperature of 66°F and a dew point of 60°F. Therefore, option (C) is correct.

The dew point can be defined as the temperature at which air should be cooled to become saturated with water vapor assuming constant air pressure and water content.

Moisture capacity will decrease below the dew point. Airborne water vapor will condense to form liquid water or dew. Dew develops on the surface and occurs through contact with a cooler surface.

The dew point is called the frost point when the temperature is below the freezing point because frost is produced by deposition rather than a condensation of water.

The humidity also impacts the dew point. The dew point increases when there is higher moisture in the atmosphere.  Therefore, the higher dew point refers to less humid air or drier.

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