Answers
Answer:
Atomic theory originated as a philosophical concept in ancient India and Greece. ... In the fifth century BCE, Democritus proposed that matter consists of indestructible, indivisible units called atoms. The Roman poet Lucretius recorded the idea, so it survived through the Dark Ages for later consideration.
Hope this is fine for youRelated Questions
Which two particles are found in the nucleus of an atom?
neutrons and electrons
protons and electrons
protons and neutrons
neutrons and atoms
Answers
Answer:
C.) protons and neutrons
Explanation:
Most atoms contain proton(s), neutron(s), and electron(s). Within the nucleus of an atom, there are protons and neutrons. Electrons are located outside of the nucleus.
The scientific method is great, but how do you think we answer the questions which cannot be tested with an experiment?
Answers
Answer:
We do something called hypothesis
Answer:
1. Make an observation.
2. Ask a question.
3. Propose a hypothesis.
4. Make predictions.
5. Test the predictions.
6. Iterate.
and if it can't be trsted the you did something wrong
Explanation:
The scientific method
At the core of biology and other sciences lies a problem-solving approach called the scientific method. The scientific method has five basic steps, plus one feedback step:
Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.
The scientific method is used in all sciences—including chemistry, physics, geology, and psychology. The scientists in these fields ask different questions and perform different tests. However, they use the same core approach to find answers that are logical and supported by evidence.
Scientific method example: Failure to toast
Let's build some intuition for the scientific method by applying its steps to a practical problem from everyday life.
Which of the following equation is correct? Can be more than one.
Answers
There are actually no disproportionation reaction in the question. They are all incomplete and unbalanced.
Example of a disproportionate reaction:
\(Cl_{2(g)}+2OH_{(aq)}^-\rightarrow Cl_{(aq)}^-+ClO_{(aq)}^-+H_2O\)For this reaction the chlorine atom on the reactant side as an oxidation state of 0. It gets reduced to -1 in Cl- and oxidized to +1 in ClO3-
Calculate the ️Hf for the following reaction:8 Al(s) + 3 Fe3O4(s) ---> 4 Al2O3(s)+ 9 Fe(s)Al2O3(s) ️Hf = -1669.8Fe3O4(s) ️Hf = -1120.9 kJ/mol
Answers
Answer
Explanation
Given data:
8Al(s) + 3Fe₃O₄(s) ---> 4Al₂O₃(s)+ 9Fe(s)
Al₂O₃(s) ️Hf = -1669.8kJ/mol
Fe₃O₄(s) ️Hf = -1120.9 kJ/mol
Step-by-step solution:
The ️Hf for the reaction can be calculated using the formula below:
\(\Delta H_f=\sum^.\Delta H_f(product)-\sum^.\Delta H_f(reactants)\)For Al(s) and Fe(s), their ΔHf is arbitrary zero.
Therefore, the ore, the ️Hf for the is:reaction
\(undefined\)For each obstacle, select the best solution. failing the classes needed to graduate from college: not being able to save enough money to pay for medical school: failing the state licensing exam:
Answers
Answer:
(A) getting study help, and retaking classes or exams
(A) applying for a loan
(C) getting study help, and retaking the exam
Explanation:
How much of 80g of sodium- 23 (Na) is left after 4 half-lives if each half-life is 2.6 years?
Answers
Answer:1
Explanation:
1
An early arrangement of the then known elements was proposed by a British scientist John Newlands, which he called the Law of Octaves. Like other scientists at the time, Newlands arranged the elements in order of increasing atomic mass and noted that every eighth element had similar physical/chemical properties. In the modern Periodic Table, which of the following represents the last pair of elements for which Newlands' Law of Octaves would hold true?
Answers
Asa watches his mom rub soap on her finger to help her get a ring unstuck. He thinks that soap must reduce friction. He designs an investigation to test his theory
Answers
Answer:
What is the question?
Explanation:
composed of proton/s, neutron/s and electron/s
Answers
Answer:
Atoms
Explanation:
Atoms are made of extremely tiny particles called protons, neutrons, and electrons. Protons and neutrons are in the center of the atom, making up the nucleus. Electrons surround the nucleus. Protons have a positive charge.
Which portion of a molecule of F2O has partial positive charge?
Question 3 options:
A)
The F atoms
B)
The central O atom
C)
The partial charge on each atom is zero
D)
The partial charge on each atom is negative
Answers
The partial charges on each fluorine atom are negative. Option B) The central O atom is the correct answer. Option B
The partial charges in a molecule are determined by the electronegativity values of the atoms involved. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. In the case of \(F_2O\), fluorine (F) is more electronegative than oxygen.
Fluorine is the most electronegative element on the periodic table, meaning it has a high ability to attract electrons. Oxygen is also relatively electronegative but less so than fluorine. When fluorine atoms bond with oxygen, the shared electrons will be pulled more towards the fluorine atoms, creating a polar covalent bond.
In \(F_2O\), each fluorine atom will pull the shared electrons towards itself, resulting in a higher electron density around the fluorine atoms. This creates a region of partial negative charge around the fluorine atoms.
Conversely, the oxygen atom will have a region of lower electron density and, therefore, a partial positive charge. This is because the shared electrons spend more time around the fluorine atoms due to their higher electronegativity.
Option B
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please write the balanced equation for the following reaction:
AI3O3 (s) + C (s) + CI2 (g) = AICI3 (s) + CO (g)
Answers
The balanced equation for the reaction is as follows:
3 AI2O3 (s) + 3C (s) + 2CI2 (g) → 3AICI3 (s) + 3CO (g)
Combination reactions happen when two or more reactants come together to create a single product. In this instance, the reactants are chlorine gas, carbon, and aluminium oxide (AI2O3) (CI2). Aluminum chloride (AICI3) and carbon monoxide make up the final product (CO). Exothermic means that energy is released when the reactants come together in this reaction. Both heat and light are manifestations of this energy. The bonds between the atoms in the reactants are broken and new bonds between the atoms in the product are formed when the reactants combine. The reaction is exothermic because of the energy released during this process.
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When a product fails to perform as warranted, this is called a) contractual liability. O b) product malfunction. c) malicious manufacture. d) breach of warranty
Answers
A block of aluminum occupies a volume of 17.8 mL and weighs 51.3 g. What is its density?
Answers
Answer:
2.88 g/mL
Explanation:
density = mass/volume
= 51.3/ 17.8
=2.88 g/mL
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In the first step of glycolysis, the given two reactions are coupled. reaction 1:reaction 2:glucose+Pi⟶glucose-6-phosphate+H2OATP+H2O⟶ADP+PiΔG=+13.8 kJ/molΔG=−30.5 kJ/mol Answer the four questions about the first step of glycolysis. Is reaction 1 spontaneous or nonspontaneous?
Answers
Answer: Reaction 1 is non spontaneous.
Explanation:
According to Gibb's equation:
\(\Delta G=\Delta H-T\Delta S\)
\(\Delta G\) = Gibbs free energy
\(\Delta H\) = enthalpy change
\(\Delta S\) = entropy change
T = temperature in Kelvin
When \(\Delta G\) = +ve, reaction is non spontaneous
\(\Delta G\)= -ve, reaction is spontaneous
\(\Delta G\)= 0, reaction is in equilibrium
For the given reaction 1: \(glucose+Pi\rightarrow glucose-6-phosphate+H_2O\) \(\Delta G=+13.8kJ/mol\)
As for the reaction 1 , the value of Gibbs free energy is positive and thus the reaction 1 is non spontaneous.
Which ecosystem is most resilient to change due to its high diversity?
mountain meadow
stormwater pond
coral reef
arctic fundra
Answers
Answer:
coral reef
Explanation:
What are the dependent and independent variables? (Picture^^)
Answers
Answer:
X axis shows the independent and Y axis shows the dependent.
Explanation:
As the independent variable is always plotted on the X-axis of the graph the Y-axis shows the dependent variable that is affected by the X variables Time is an independent variable and is always shown along the X-axis. Such as the image showed tells about the data of N2O biofuel emissions from 2009-10. Thus this will be plotted along the X-axis and Y-axis will show the amount of nitrogen fertilizer applied.Directions: Please show all work, round each answer the correct number of significant figure
and include units where appropriate.
d) [H] = 4.52 x 10 M
Date:
Unit: Acids, Bases, and Solutions
"Acid/Base Calculations" - WS #4
1. Calculate the pH of the solutions, given the following [H], and then identify the solution
as acidic, basic, or neutral.
a) [H'] = 1.2 x 10¹ M
b) [H] = 5.8 x 10° M
c) [H] - 3.92 x 10" M
b) pH = 11.7+9
c) pH=6.8
2. Calculate the [H] in the following solutions, given their pH, and identify the solution as
acidic, basic or neutral.
a) pH = 2.5
d) pH = 3.31
Class period:
3. Given the following pOH's, calculate the pH for the solution:
a) pOH = 4.18
b) pOH = 12.35
4. Given the following pH's, calculate the pOH for the solution:
a) pH = 6.2
b) pH=9.55
Answers
The solutions ae all acidic with pH less than 7.
a) To calculate the pH of a solution with [H+] = 1.2 x 10^(-1) M:
pH = -log[H+]
pH = -log(1.2 x 10^(-1))
pH = -log(1.2) + log(10^(-1))
pH = -log(1.2) - 1
pH ≈ 0.92
The solution is acidic.
b) To calculate the pH of a solution with [H+] = 5.8 x 10^0 M:
pH = -log[H+]
pH = -log(5.8 x 10^0)
pH = -log(5.8)
pH ≈ 0.24
The solution is acidic.
c) To calculate the pH of a solution with [H+] = 3.92 x 10^(-3) M:
pH = -log[H+]
pH = -log(3.92 x 10^(-3))
pH ≈ 2.41
The solution is acidic.
a) To calculate [H+] in a solution with pH = 2.5:
[H+] = 10^(-pH)
[H+] = 10^(-2.5)
[H+] ≈ 3.16 x 10^(-3) M
The solution is acidic.
b) To calculate [H+] in a solution with pH = 3.31:
[H+] = 10^(-pH)
[H+] = 10^(-3.31)
[H+] ≈ 4.54 x 10^(-4) M
The solution is acidic.
a) To calculate the pH for a solution with pOH = 4.18:
pOH + pH = 14
pH = 14 - pOH
pH = 14 - 4.18
pH ≈ 9.82
b) To calculate the pH for a solution with pOH = 12.35:
pOH + pH = 14
pH = 14 - pOH
pH = 14 - 12.35
pH ≈ 1.65
a) To calculate the pOH for a solution with pH = 6.2:
pOH + pH = 14
pOH = 14 - pH
pOH = 14 - 6.2
pOH ≈ 7.8
b) To calculate the pOH for a solution with pH = 9.55:
pOH + pH = 14
pOH = 14 - pH
pOH = 14 - 9.55
pOH ≈ 4.45
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What is and ionic bond and how it forms and why it forms
Answers
Which statement is true about sound waves?
They move faster than light.
They make wind.
They vibrate the air.
They move slower in water than in air.
Answers
Answer:
the last one, cuz water has a resistance force which slows it down
Explanation:
Answer: C They vibrate the air
Explanation: Edge 22
What is the chemical name of the compound Na2CO3? Use the list of polyatomic ions and the periodic table to help you answer.
A.
sodium carbon oxide
B.
sodium carbonate
C.
sodium(II) carbonate
D.
sodium oxalate
Answers
Answer:
sodium carbonate
Explanation:
sodium carbonate
Answer the question please
Answers
Answer:
Density=1.006 g/cm^3 .
Detailed explanation in screenshot attached below
Explanation:
A graduated cylinder was filled to 20.3 mL with water. A solid object weighing 73.05 g was immersed in the water, raising the meniscus of the water to 48.1 mL. Calculate the density of the solid object in g/mL.
Answers
The density of the solid object will be 2.63 g/mL
What is density?Density of objects = mass/volume.
Recall that an object will always displace its own volume when placed in a liquid.
Volume of the solid object = Cylinder reading after immersing the object in the water - cylinder reading before immersing the object in the water.
= 48.1 - 20.4
= 27.8 mL
Mass of the solid object = 73.05 g
Density of the object = 73.05/27.8
= 2.63 g/mL
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In the following reaction how many moles of NaCI are needed to produce 5.4 miles of Na2O
NaCI+MgO= Na2O+MgCI2
Answers
To produce 5.4 moles of \(Na_{2} O\) in the given reaction, 10.8 moles of NaCl are required.
The given chemical equation is a balanced equation, which means it represents the stoichiometric relationship between the reactants and products involved in the reaction.
The coefficients of the balanced equation represent the number of moles of each reactant and product involved in the reaction.
In this case, the equation is:
2 NaCl + MgO → \(Na_{2} O\) + \(MgCl_{2}\)
From the equation, we can see that 2 moles of NaCl are required to produce 1 mole of . Therefore, to produce 5.4 moles of \(Na_{2} O\), we need to use stoichiometry to determine the amount of NaCl required.
We can use the following formula to calculate the number of moles of NaCl required:
moles of NaCl = moles of \(Na_{2} O\) × (2 moles NaCl / 1 mole \(Na_{2} O\))
Substituting the given values, we get:
moles of NaCl = 5.4 moles \(Na_{2} O\) × (2 moles NaCl / 1 mole \(Na_{2} O\)) = 10.8 moles NaCl
Therefore, we need 10.8 moles of NaCl to produce 5.4 moles of \(Na_{2} O\) in the given reaction.
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Which energy resource causes the greatest waste disposal concerns?
solar power
nuclear
coal
geothermal power
Answers
During the reaction: Mg(s) + CuSO4(aq)
es)
MgSO4(aq) + Cu(s), what changes occur to magnesium?
A)Its oxidation number changes from +2 to 0 and it is reduced.
B)Its oxidation number changes from 0 to +4 and it is reduced.
C)Its oxidation number changes from 0 to +2 and it is oxidized.
D)Its oxidation number changes from +2 to +4 and it is oxidized.
Answers
Answer:
C
Explanation:
I did it on usatestprep
HELPPPPPPPPP 35 POINTSSSSSS!!!!!
A metal is oxidized if it’s converted from its metallic form to make a compound, and it’s reduced if it’s converted back to its metallic form.
FILL IN THE BLANKS with either "reduce" or "oxidize"
Magnesium is able to copper, and copper is able to magnesium.
Zinc is able to magnesium, and magnesium is able to zinc.
Copper is able to zinc, and zinc is able to copper.
Answers
Answer:
oxidize
Explanation:
In the electrolysis of water, the 50 cm3 of a gas is obtained at the anode. a. Write the chemical equation. b. What is the gas obtained at the anode? c. What is the volume of gas obtained at the anode?
Answers
a. The chemical equation for the electrolysis of water is:
2H2O(l) → 2H2(g) + O2(g)
b. The gas obtained at the anode during the electrolysis of water is oxygen (O2).
c. The volume of gas obtained at the anode is 0.002232 moles or approximately 0.05 L of oxygen gas.
a. The chemical equation for the electrolysis of water is:
2H2O(l) → 2H2(g) + O2(g)
b. The gas obtained at the anode during the electrolysis of water is oxygen (O2).
c. According to the balanced chemical equation, for every 2 moles of water (H2O) electrolyzed, 1 mole of oxygen gas (O2) is obtained. Since 1 mole of any gas occupies 22.4 L at standard temperature and pressure (STP), we can use the stoichiometry of the reaction to determine the volume of oxygen gas produced.
Given that 50 cm³ of gas is obtained at the anode, we need to convert this volume to liters:
50 cm³ = 50/1000 L = 0.05 L
Using the stoichiometric ratio of the balanced equation, we find that 2 moles of water produce 1 mole of oxygen gas. Therefore, 0.05 L of oxygen gas is equivalent to:
0.05 L × (1 mole/22.4 L) = 0.002232 moles
Thus, the volume of gas obtained at the anode is 0.002232 moles or approximately 0.05 L of oxygen gas.
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Given: H2 + O 2 → H2O1
the reaction occurs at ST.P a) Balance the chemical equation. (1 pts) b) Calculate the number of moles of the reactants needed to obtain 45 liner of H2O (2 pt) 4) Deduce the volume of the reactants (2 pts)
Answers
a) The balanced chemical equation for the reaction is: 2H₂ + O₂ → 2H₂O
b) the number of moles of O₂ required is approximately 1.004 moles.
c) approximately 45 liters of H₂ and 22.5 liters of O₂ are needed to obtain 45 liters of H₂O.
a) Balancing the chemical equation:
The balanced chemical equation for the reaction is: 2H₂ + O₂ → 2H₂O
b) Calculating the number of moles of the reactants needed to obtain 45 liters of H₂O:
From the balanced equation, we can see that for every 2 moles of H₂O produced, we need 2 moles of H₂ and 1 mole of O₂. Since the stoichiometry is based on moles, we need to convert the given volume of H2O into moles.
To convert volume to moles, we need to use the ideal gas law, PV = nRT. At standard temperature and pressure (STP), the molar volume of an ideal gas is 22.4 liters.
Given that we have 45 liters of H2O, we can calculate the number of moles as follows:
moles of H₂O = (volume of H₂O) / (molar volume at STP)
= 45 liters / 22.4 liters/mol
≈ 2.008 moles of H₂O
Since the stoichiometry of the reaction is 2 moles of H₂O for every 2 moles of H₂, we need an equal number of moles of H₂. Therefore, the number of moles of H₂ required is also approximately 2.008 moles.
For O₂, since the stoichiometry is 1 mole of O₂ for every 2 moles of H₂O, we need half the number of moles of H₂O. Thus, the number of moles of O₂required is approximately 1.004 moles.
c) the volume of the reactants:
Since the stoichiometry of the balanced equation is 2 moles of H₂for every 1 mole of O₂ and 2 moles of H₂O, we can deduce the volume of the reactants based on their molar volumes at STP.
For 2.008 moles of H₂, the volume can be calculated as follows:
volume of H₂= (moles of H₂) * (molar volume at STP)
= 2.008 moles * 22.4 liters/mol
≈ 45 liters of H₂
For 1.004 moles of O₂, the volume can be calculated similarly:
volume of O₂= (moles of O₂) * (molar volume at STP)
= 1.004 moles * 22.4 liters/mol
≈ 22.5 liters of O₂
Therefore, approximately 45 liters of H₂and 22.5 liters of O₂ are needed to obtain 45 liters of H₂O
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What quantity of heat is transferred when a 150.0g block of iron metal is heated from 25.0°C to 73.3°C? What is the direction of the heat flow?
Answers
The direction of heat flow is increased which means blocks temperature is higher and hotter than it was before
How many moles of H2 will be produced from 100 moles of water?2 H2O → 2 H2 + O2
Answers
In order to answer this question, we are going to look at the molar ratio between H2O and H2, we can see that by analyzing the numbers in front of the compounds, and we can see that the molar ratio is 2:2, this means that for every 2 moles of water decomposing, we will end up with 2 moles of H2 being produced, therefore the same amount of moles for H2O will be the same amount of moles of H2, which means that if we have 100 moles of H2O being decomposed, we will also have 100 moles of H2 being produced.