I'm a little confused so can someone check my answers-

1. Which of the following is true about alchemists and alchemy?
Alchemy is a science.
Chemistry developed into alchemy.
Alchemists tried to turn metals into gold. (My answer)
Robert Boyle was an alchemist.

2. Which of the following is alchemy?
A medieval pseudoscience that tried to find ways to change ordinary metals into gold. (My answer)
The discovery that atoms have a unique structure of protons, neutrons, and electrons.
A systematic process of gaining knowledge by observing and testing.
The modern science of chemistry.

3. In which case are medicines based on science rather than pseudoscience?
If the medicines save lives or help many people.
If the medicines have been evaluated using unbiased tests. (My answer)
If the people who create the medicines have science or medical degrees.
If the medicines have been used for many years.

4. Which option describes a science question?
One that can be answered through hypotheses.
One that can be answered through inferences.
One that can be answered by observations of nature.
One that can be answered by investigation. (My answer)

5. Which inference can be made from the fact that Fritz Haber received a Nobel Prize in 1918?
The Haber-Bosch process was an important scientific development.
The Haber-Bosch process was used to make explosives in World War I. (My answer)
The Haber-Bosch process made the world more peaceful.
The Haber-Bosch process initially only made small quantities of ammonia.

Any help with this is appreciated

Answer:

DNA

Explanation:

because genetics come from DNA

Answer:

15.26 cm³

Explanation:

La densidad de una sustancia se define como su masa por unidad de volumen:

densidad = masa/volumen

Tenemos los siguientes datos de la barra de hierro:

masa = 160 g

volumen = 20,35 cm³

Por lo tanto, la densidad de la barra de hierro es:

densidad = 160 g/20,35 cm³ = 0.786 g/cm³

El volumen de 12 gramos de hierro se calcula utilizando el dato de masa (12 g) y la densidad calculada:

densidad = masa/volumen  ⇒ volumen = masa/densidad

                                                                 = 12 g/(0.786 g/cm³)

                                                                 = 15.26 cm³

Answer:

Yes its vinegar

Explanation:

Actually [tex] \bold{\red {C_2H_4O_2}} [/tex] is the formula for acetic acid which is found in vinegar.

Answer:

too many greenhouse gases can cause the temperature to increase out of control. ... The increased greenhouse effect is causing changes in our planet that can affect our lives. The major Greenhouse Gas, carbon dioxide, emitted naturally and by the burning of fossil fuels, stays in the atmosphere a long

Effects: By increasing the concentration of greenhouse gases in the atmosphere, we’re amplifying the planet’s natural greenhouse effect and turning up the dial on global warming.

The atmosphere of the Earth may begin to trap more and more heat if these greenhouse gases are present in excess. Earth warms as a result of this.

A greenhouse gas is a gas that produces the greenhouse effect by both absorbing and emitting radiant energy at thermal wavelengths that are infrared. The five main greenhouse gases in the atmosphere of Earth are ozone, carbon dioxide, methane, and water vapour.

Carbon dioxide, methane, nitrous oxides, and water vapour are examples of greenhouse gases. (A "feedback" is the term used to describe water vapor, which reacts chemically or physically to changes in temperature.) Scientists have found that the warming effect of carbon dioxide contributes to the stabilisation of Earth's atmosphere.

Thus, the atmosphere of the Earth may begin to trap more and more heat if these greenhouse gases are present in excess. Earth warms as a result of this.

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Answer:

c20 will be there ok

Explanation:

okbbbbbbbbbbyyyyyyyy

Answer:

84 g of N₂        

Explanation:

We begin from the reaction:

N₂O₄  +  2N₂H₄ →  3N₂  + 4H₂O

  1st step: Find out the limiting reactant.

We convert the mass to moles.

       276 g . 1mol/ 92g = 3 moles of N₂O₄

64 g . 1mol / 32g = 2 moles of hidrazine  

Limiting reactant is the hydrazine. Ratio is 1:2, then for 3 moles of tetroixde I may need 6 moles of N₂H₄. (But I only have 2).

To determine the grams of produced nitrogen we see stoichiometry (2:3)    

2 moles of hydrazine can produce 3 moles of N₂

Definetaly our 2 moles make 3 moles of gas.

We convert the moles to mass.

3 mol . 28g /1mol = 84 g of N₂                                                                                                

Answer:

31.24 kJ

Explanation:

First we convert 3.00 grams of SiO₂ to moles, using its molar mass:

Now we calculate the heat absorbed, using the given ΔH°:

If the complete reaction of 1 mol of SiO₂ absorbs 624.7 kJ, then with 0.05 mol:

The heat absorbed by 3.00 grams of SiO2 is 31.17 kJ/mol.

The thermochemical equation is;

SiO2(g) + 3C(s) → SiC(s) + 2CO(g) ΔH° = 624.7 kJ/mol

The number of moles of SiO2 = 3.00 g/60.08 g/mol = 0.0499 moles

From the reaction equation;

1 mole of SiO2 absorbs 624.7 kJ/mol

0.0499 moles SiO2 absorbs  0.0499 moles ×  624.7 kJ/mol/1 mole

= 31.17 kJ/mol

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Answer:

you did not posted the series

Explanation:

Answer:

498 g

0.498 kg

Explanation:

Answer:

4.498 kg

1.47

35.0

51.5

Explanation:

Answer:

first balance the reaction

n2 + 3h2 --> 2NH3

then you have your ratios

so for every mole of N2 you get 2 NH3

so 8.4mol is your answer

Explanation:

Answer:

Noble gasses

Explanation:

nobled gasses

all elements want to loose or gain electrons to be like the noble gasses in bonding but the noble gasses do not bond.

Answer:

D

Explanation:

Reacting with acid is the only chemical property out of the 4 options. The rest are physical

Answer:

0.500 liters

Explanation:

Answer:

20 protons , 20 electrons and 20 neutrons

Answer: The molecular formula will be [tex]C_6H_6O[/tex]

Explanation:

Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.  

Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.

The empirical formula is [tex]C_6H_6O[/tex]

The empirical weight of [tex]C_6H_6O[/tex] = 6(12)+6(1)+1(16) = 94 g.

The molecular weight = [tex]2\times \text{vapour density}=2\times 47=94[/tex]

Now we have to calculate the molecular formula.

[tex]n=\frac{\text{Molecular weight}}{\text{Equivalent weight}}=\frac{94}{94}=1[/tex]

The molecular formula will be=[tex]1\times C_6H_6O=C_6H_6O[/tex]

sublimation is the transition of a substance directly from the solid to the state without passing through the liquid state

Answer:

If the available number of valence electrons for a molecule or ion does not complete all of the octets, then multiple bonds must be drawn.

Explanation:

If the available number of valence electrons for a molecule or ion does not complete all of the octets, then multiple bonds must be drawn.

We must note that Lewis structures are representations of molecules Using dots to show the number of valence electrons on the valence shell of the atoms of  each of the constituent elements in the molecule. Each atom is expected to have an octet of electrons on its outermost shell.

Many times, we encounter Lewis structures in which the octet of some atoms are incomplete. This means that the atoms have less than eight outermost electrons.

In such cases, we must invoke the idea of multiple bonds to account for the incomplete octet.

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Answer:

p = 36400 kg·m/s

Explanation:

p=mv

p= Momentum

m= mass (1300 kg)

v= 28

1300 × 28

= 36400 kg·m/s

The Momentum of the car is 36400 kg-m/s.

Momentum is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction.  m is an object's mass and v is its velocity

Given that,

(m is an object's mass and v is its velocity)

To find :

The momentum of car, p

Solve :

Let p is the momentum of an object. It can be calculated by the product of mass and its velocity. The formula to find it is given by :

p = m x v

  = 1300 x 28

  = 36400 kg-m/s.

Therefore, the momentum of the car is 36400 kg-m/s.

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Answer:

Fractional distillation

Explanation:

The process of separating petroleum products into its fractions is called fractional distillation.

Fractional distillation is a method of separating a mixture of substances based on the differences in their boiling points.

Petroleum is a mixture of hydrocarbons separated in a large fractionation tower having many trays maintained at different temperatures.

As the vapor containing the petroleum mixture ascends the fractionation tower, the mixture is separated at each tray to yield the various fractions of petroleum.

Answer and Explanation:

Ions are electrically charged particles that are formed from the removing and addition of electrons. It can be a positively or negatively charged atom.

Answer:

Enteric Nervous System

The enteric nervous system (ENS) is a subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system.

LEARNING OBJECTIVES

Describe the structure and function of the enteric nervous system (ENS)

KEY TAKEAWAYS

Key Points

The enteric nervous system (ENS), which is embedded in the lining of the gastrointestinal system, can operate independently of the brain and the spinal cord.

The ENS consists of two plexuses, the submucosal and the myenteric. The myenteric plexus increases the tone of the gut and the velocity and intensity of contractions. The submucosal plexus is involved with local conditions and controls local secretion, absorption, and muscle movements.

While described as a second brain, the enteric nervous system normally communicates with the central nervous system (CNS) through the parasympathetic (via the vagus nerve ) and sympathetic (via the prevertebral ganglia) nervous systems, but can still function when the vagus nerve is severed.

The ENS includes efferent neurons, afferent neurons, and interneurons, all of which make the ENS capable of carrying reflexes and acting as an integrating center in the absence of CNS input.

The ENS contains support cells, which are similar to the astroglia of the brain, and a diffusion barrier around the capillaries surrounding the ganglia, which is similar to the blood –brain barrier of cerebral blood vessels.

Key Terms

enteric nervous system: A subdivision of the peripheral nervous system that directly controls the gastrointestinal system.

EXAMPLES

The second brain of the enteric nervous system is the reason we get butterflies in our stomach or need to use the restroom more frequently when we are nervous and/or under stress.

The gastrointestinal (GI) system has its own nervous system, the enteric nervous system (ENS). Neurogastroenterology is the study of the enteric nervous system, a subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system. The ENS is capable of autonomous functions such as the coordination of reflexes.

Although it receives considerable innervation from the autonomic nervous system, it can and does operate independently of the brain and the spinal cord. The ENS consists of some 100 million neurons, one-thousandth of the number of neurons in the brain, and about one-tenth the number of neurons in the spinal cord. The enteric nervous system is embedded in the lining of the gastrointestinal system.

Ganglia of the ENS

The neurons of the ENS are collected into two types of ganglia:

The myenteric (Auerbach’s) plexus, located between the inner and outer layers of the muscularis externa

The submucosal (Meissner’s) plexus, located in the submucosa

The Myenteric Plexus

The myenteric plexus is mainly organized as a longitudinal chains of neurons. When stimulated, this plexus increases the tone of the gut as well as the velocity and intensity of its contractions. This plexus is concerned with motility throughout the whole gut. Inhibition of the myenteric system helps to relax the sphincters —the muscular rings that control the flow of digested food or food waste.

The Submucosal Plexus

The submucosal plexus is more involved with local conditions and controls local secretion and absorption, as well as local muscle movements. The mucosa and epithelial tissue associated with the submucosal plexus have sensory nerve endings that feed signals to both layers of the enteric plexus. These tissues also send information back to the sympathetic pre-vertebral ganglia, the spinal cord, and the brain stem.

This is an illustration of neural control of the gut wall by the autonomic nervous system and the enteric nervous system. A sensory neuron is shown to stimulate the nerves in the submucosal and myenteric plexuses, which are connected to nerves in the sympathetic and parasympathetic nervous systems. The sensory neuron is also shown signal the ganglia and central nervous system.

Neural control of the gut: An illustration of neural control of the gut wall by the autonomic nervous system and the enteric nervous system.

Function and Structure of the ENS

The enteric nervous system has been described as a second brain. There are several reasons for this. For instance, the enteric nervous system can operate autonomously. It normally communicates with the central nervous system (CNS) through the parasympathetic (e.g., via the vagus nerve) and sympathetic (e.g., via the prevertebral ganglia) nervous systems. However, vertebrate studies show that when the vagus nerve is severed, the enteric nervous system continues to function.

Explanation:

Answer:

I'm sorry but there is no diagram above.

Answer:

7.224 × 10^28 atoms

Explanation:

The number of moles contained in a substance (n) can be calculated from this expression:

nA = n × 6.02 × 10^23 atoms

Where;

nA = number of atoms of substance

n = number of moles of substance

Avagadro's number or constant = 6.02 × 10^23 atoms

Using nA = n × 6.02 × 10^23 atoms

In this question, there are 1.2 x 10^5 moles of neon (N). The number of atoms (nA) is as follows:

nA of neon = 1.2 x 10^5 × 6.02 × 10^23

nA = 7.224 × 10^ (5 + 23)

nA = 7.224 × 10^28 atoms

The number of neon atoms in 1.2 x 10^5 is 7.224 × 10^28 atoms.

D. The molecular motion of the substance changes.