Who thought fire was one of four elements?
O A. Aristotle
O B. Marie Curie
O C. John Dalton
O D. Robert Boyle

Answers

Answer 1

Answer:

D Robert Boyle

Explanation:

Answer 2
I would say it is A. Aristotle

Related Questions

Tom pushes on a 50-kilogram box with a force of 25 newtons. Assuming the surface on which the box moves is frictionless, at what rate does the box accelerate?

Answers

Assuming the surface on which the box moves is frictionless, the rate at which the box accelerate is equal to 0.5 [tex]m/s^2[/tex].

Given the following data:

Mass of box = 50 kilogramForce = 25 newtons.

To determine the rate at which the box accelerate, assuming the surface on which the box moves is frictionless:

Mathematically, Newton's Second Law of Motion is given by the formula;

[tex]Force = mass \times acceleration[/tex]

Making acceleration the subject of formula, we have:

[tex]Acceleration =\frac{Force}{mass}[/tex]

Substituting the given parameters into the formula, we have;

[tex]Acceleration = \frac{25}{50}[/tex]

Acceleration = 0.5 [tex]m/s^2[/tex]

Read more on Newton's Law of Motion here: https://brainly.com/question/1121817

Select from the unit conversion factor options below to determine the mass in grams of 1.204 × 1024 atoms of carbon.
1 mol C/ 6.02 x 1023 atoms C, 6.02 x 1023 atoms C / 1 mol C
12 g C / 1 mol, 1 mol / 12 g C



a
12040 g
b
24 g
c
204 g
d
1.99 g

Answers

Answer:

option a is the answer

Explanation:

bye bye


True or False? The energy carried by a sound
wave is blocked by collisition
between the particles in the
material the name is traveling
in

Answers

Answer:

true

Explanation:

i checked on moogle

True Is the answer ..scientific proved .

An atom which has 9 protons, 8 neutrons, and 9 electrons will have an atomic mass of how many amu?

a. 6

b. 8

C. 9

d. 17

Answers

Answer:

D

Explanation:

Protons and Neutrons both have a mass of about 1 amu so you add them but electrons have a mass of 0 amu so they are left out.

if a substance has a normal boiling point of 50 °c, what can you state about the vapor pressure of the same substance at 40 0 °c?

Answers

It will be less because pressure is directly proportional to temperature

Pls help if you only know the correct answer! Thanks!!

Answers

Answer:

1. H=2, O=1

2. H=4, O=2

3. C=1, O=1

4.

a. reactants C=1, O=2

b. products C=1, O=2

5.

a. reactants H=4, O=2

b. products H=4, O=2

6

a. reactants C=1, O=1, H=4

b. products C=1, O=1, H=4

7. Which white blood cells help to get rid of good cells that have been infected by a pathogen? *
(2 Points)

A. T cells

B. B cells

Answers

Answer:

B cells and T cells. The B cells produce antibodies that are used to attack invading bacteria, viruses, and toxins. The T cells destroy the body's own cells that have themselves been taken over by viruses or become cancerous.

Explanation:

Which statement best defines kinetic energy? A. kinetic energy is highest at the highest point of structure or model.
B. kinetic energy is stored in a battery.
C. kinetic energy is energy that is stored up. D. kinetic energy is the energy of motion. help me pls!!​

Answers

Answer:

The answer is D. Kinetic energy is the energy of motion.

Pls mark brainliest. Hope this helped. :D

the answer is d because potential energy is the energy that is stored

What do you already know about gases?

Answers

Answer:

gasese molecules are always in free state

A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material?.

Answers

Whether it conducts heat or electricity,if it is attracted by a magnet , high density high melting point

The question that will best help the student to classify the material is; "is the material malleable or ductile?"

Generally, materials can be classified as metals or non metals. There are properties that are particular to metals and there are properties that are particular to nonmetals and these properties can be used to identify each one of the materials.

The question that will best help the student to classify the material is; "is the material malleable or ductile?" These metallic properties.

Learn more:

https://brainly.com/question/1659592

Missing parts;

A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material? A. Is the material malleable or ductile? B. Does the material feel hard to the touch? C. Will the material float in water? D. Does the material feel rough or smooth?

rank the crystal lattice structures in order of decreasing efficiency of space in the structure.

Answers

Rank the crystal lattice structures in order of decreasing efficiency of space in the structure.

1. Simple cubic

2. Body centered cubic

3. Face centered cubic

4. Hexegonal close packed

How many sig figs are in 6.0395? Please no links-

Answers

Answer:

5 significant figures

Explanation:

The zeros as considered when they are in between or after numbers greater than zero.

Ex1: 0.005 = 1 significant figure

Ex2: 0.0050 = 2 significant figure

Ex3: 0.05500= 4 significant figure

Ex4: 5.00 = 1 significant figure

Determine the mass of O(2-) ions in 3 mol of alumina (Al2O3). Molar mass of O = 16)

Answers

Considering the rule of three and molar mass of O, the mass of O²⁻ ions in 3 mol of alumina Al₂O₃ is 96 grams.

By multiplying the number of moles by the subscripts next to each atom, you get the amount of each element present in the compound. IIf the same atom appears more than once in the compound, you must add its amounts.

So, in 1 mole of Al₂O₃, you have 2 ions of O²⁻.

Then you can apply the following rule of three: if 1 mole of the compound contains 2 ions of O²⁻, 3 moles of the compound contains how many ions of O²⁻?

[tex]amount of ions of O^{2-} =\frac{3 moles of Al_{2} O_{3} x2 ions of O^{2-}}{1mole of Al_{2} O_{3} }[/tex]

amount of ions of O²⁻= 6 ions

Being the molar mass of O 16 g/mole, this is the amount of mass that a substance contains in one mole, then the mass of O²⁻ can be calculated as:

6 x 16 g/mole= 96 grams

Finally, the mass of O²⁻ ions in 3 mol of alumina Al₂O₃ is 96 grams.

Learn more about molar mass:

https://brainly.com/question/3588290?referrer=searchResultshttps://brainly.com/question/25873251?referrer=searchResults

PLEASE HELP I AM FAILING

Answers

Answer:

160.3 g S

Explanation: there you go

How did President Wilson anger civil rights advocates?

Answers

Answer:

He put segregationists in charge of federal agencies...

Explanation:

...

Answer:

He placed segregationists in charge of federal agencies.

Explanation:

20. A way to describe a chemical reaction
a. Equations
c. Molecules
b. Metals
d. Elements

Answers

D. Elements

Hope this helps

(iii) Give two reasons why the electrolyte contains cryolite​

Answers

Answer:

The mixture of cryolite and aluminum oxide has a lower melting point than pure aluminum oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.

Explanation:

Oxygen is produced by the reaction of sodium peroxide, Na2O2 , and water.
2 Na2O2 (s) + 2 H2O(l) ---> O2(g) + 4 NaOH(aq)
Calculate the mass of Na2O2 in grams needed to form 5.20 g of oxygen.

Answers

Answer: 23.53g

Explanation:

5.2/(2x16) = 0.1625 mol

0.1625 x 2 = 0.325 mol

0.325 x (23 x 2 + 16 x 2) = 78 x 0.325 = 23.53g

Give an example for the neutralisation between a strong acid and a weak base, also mention the nature of its salt.​

need help !! ~~~~

Answers

Answer:

Neutralization occurs when a strong acid and a strong base come together in a chemical reaction to form water and salt.

Explanation:

not sure huhuhu

Give one example of how environmental factor could influence the way a gene is expressed.

Answers

Answer:

The presence of drugs or chemicals in an organisms environment can also influence gene expression in the orgains.

Match each type of reaction to its amount of potential energy. (PLEASE HELP )

Answers

Endo is more in reactants and exo is more in products because in exothermic reactions heat is released

Which objects refract light? (Select all that apply.)
the human eye
contact lenses
a magnifying glass
concave mirrors

Answers

Concave mirrors, magnifying lens... sorry not sure about the rest
Magnifying glass and concave mirrors


2. How many MOLES of cobalt(III) sulfate are present in 4.25 grams of this compound?
moles.

Answers

Answer:

1 grams Cobalt(II) Sulfate = 0.006451787725861 mole using the molecular weight calculator and the molar mass of CoSO4.

Explanation:

Read the following chemical equations.

Reaction 1: 2KI + H2O2 2KOH + 12
Reaction 2: Cl2 + H2 → 2HCI

Which of the following statements is true for both the chemical equations?

A. I is oxidized in reaction 1 and Cl2 is oxidized in reaction 2.

B. I is reduced in reaction 1 and Cl2 is reduced in reaction 2.

C. I is oxidized in reaction 1 and Cl2 is reduced in reaction 2.

D. I is reduced in reaction 1 and Cl2 is oxidized in reaction 2.​

Answers

This problem is providing two reduction-oxidation (redox) reactions in which the oxidized and reduced species can be identified by firstly setting the oxidation number of each element:

Reaction 1: 2K⁺I⁻ + H₂⁺O₂⁻  ⇒2K⁺O⁻²H⁺ + I₂⁰

Reaction 2: Cl₂⁰ + H₂⁰ ⇒ 2H⁺CI⁻

Next, we can see that iodine is being oxidized and oxygen reduced in reaction #1 and chlorine is being reduced and hydrogen oxidized in reaction #2 because the oxidized species increase the oxidation number whereas the reduced ones decrease it.

In such a way, the correct choice is C.

Learn more:

(Redox reactions) https://brainly.com/question/13978139

Which of these is found in the energy levels of an atom?

Answers

Answer:

Electrons

Explanation:

Because the nucleas is In the middle and the Electrons surround it

NO LINKS!!!
Help . . .

Where is the magnetic field strongest?
A. closest to the wire
B. Farthest from the wire

Answers

Answer:

In general, the magnetic field is strongest close to the wire and weaker farther away. In fact, the magnetic field weakens as 1/r1/r where rr is the distance from the wire. This can change a bit depending on the length and shape of the wire. Far enough away, the magnetic field decays as 1/r21/r2 .

Answer:

Closest to the wire

Explanation:

In general, the magnetic field is strongest close to the wire and weaker farther away. In fact, the magnetic field weakens as where is the distance from the wire. This can change a bit depending on the length and shape of the wire.


Pls answer rn due tmr pls pls fast

Answers

Answer:

From bottom to top, Troposphere, Stratosphere, Mesosphere, Thermosphere, & at the top, Exosphere.

Explanation:

please help fast thank yuo

Answers

Answer:

what is your question tell may i can help you

Answer:

decrease as we go down a group I know ionisation energy increases from left to right across the periodic table

2 WHAT ARE THE THREE THINGS NECESSARY TO MAINTAIN A FIRE?

Answers

Oxygen, heat, and fuel

Answer:

Oxygen, heat, and fuel

Explanation:

Oxygen, heat, and fuel are frequently referred to as the "fire triangle." Add in the fourth element, the chemical reaction, and you actually have a fire "tetrahedron." The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.

How many moles of AgCl can form from 6.5 moles of Ag and abundant HCl in the equation: 2Ag + 2HCl -> 2AgCl + H2

Answers

6.5 moles of AgCl can be formed from 6.5 moles of Ag.

STOICHIOMETRY:

According to this question, silver reacts with hydrochloric acid to form silver chloride and hydrogen gas as follows:

2Ag + 2HCl → 2AgCl + H2

Based on this balanced equation, 2 moles of silver (Ag) produces 2 moles of silver chloride (AgCl).

This means that 6.5 moles of Ag will produce (6.5 × 2)/2 = 6.5 moles of AgCl.

Learn more about stoichiometry at: https://brainly.com/question/9743981?referrer=searchResults

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