Answer:
Creativity can help scientists by leading them to ask more questions about the natural world.
Explanation:
Beacause they use creativity to make up questions about the natural world.
Many scientists have contributed to the atomic theory. In 1803 John Dalton gave new insight to this theory. Which desciption of an atom fits our most
current understanding?
Fyry nyyden atom is the same as every hydrogen atom
Please help I need to turn this in already
Answer:
The acceleration will be .5 and the force will be 37.5
Have a nice day! :)
Answer:
Hello. The answer is 37.5N.
Explanation:
If you look carfully ، every time that you add one weight the force changes 2.5N so you can do this:
[tex](2.5 \times 5) + 25 = 37.5[/tex]
When 2.16g of H2 reacts with excess O2 by the following equation, 258 kJ of heat are released. What is the change of enthalpy associated with the reaction of 1.00 mol of hydrogen gas? 2H2+O2⟶2H2O
Answer:
-241 kJ/mol
Explanation:
Let's consider the reaction of hydrogen with excess oxygen to form water.
2 H₂ + O₂ ⟶ 2 H₂O
When 2.16g of hydrogen reacts with excess oxygen, 258 kJ of heat are released, that is, Q = -258 kJ. Considering that the molar mass of hydrogen is 2.02 g/mol, the change of enthalpy associated with the reaction of 1.00 mol of hydrogen gas is:
ΔH° = -258 kJ/2.16 g × (2.02 g/1.00 mol) = -241 kJ/mol
A sample of sodium bicarbonate is placed in an evacuated container at allowed to reach equilibrium. What will be the total pressure?
Complete Question
Sodium carbonate, Na2CO3(s), can be prepared by heating sodium bicarbonate, NaHCO3(s).
2NaHCO3(s) ------> Na2CO3(s) + CO2(g) + H2O(g) Kp = 0.23 at 100oC
If a sample of NaHCO3 is placed in an evacuated flask and allowed to achieve equilibrium at 100oC, what will the total gas pressure be?
Answer:
The value is [tex]P_T = 0.959 \ atm [/tex]
Explanation:
From the question we are told that
The equation is
[tex]2NaHCO_3_{(s)} \rightarrow Na_2CO_3_{(s)} + CO2_{(g)} + H2O_{(g)}[/tex]
Generally the equilibrium partial pressure is mathematically represented as
[tex]K_p = P_{CO_2} + P_{H_2O}[/tex]
Here
[tex] P_{CO_2} \ and \ P_{H_2O}[/tex] are partial pressures of [tex] CO_2 \ and \ H_2O [/tex] gases
Note: when writing the formula for equilibrium partial pressure we consider only the gas in the reaction
Let assume that
[tex]P_{CO_2} = a[/tex]
Generally [tex]P_{CO_2} = P_{H_2O}[/tex] since they are both products of the reaction
So
[tex]K_p = a^2 [/tex]
From the question we are told that [tex]K_p = 0.23 [/tex]
So
[tex] 0.23= a^2 [/tex]
=> [tex] a = \sqrt{0.23} [/tex]
=> [tex] a = \sqrt{0.23} [/tex]
=> [tex] a = 0.4796 \ atm [/tex]
So
[tex]P_{CO_2} = 0.4796 \ atm[/tex]
and
[tex]P_{H_2O} = 0.4796 \ atm [/tex]
So the total pressure is
[tex]P_T = 0.4796 + 0.4796[/tex]
=> [tex]P_T = 0.959 \ atm [/tex]
a. Describe the molecule chlorine dioxide, CIO in terms of three possible resonance structures.
b. Do any of these resonance structures satisfy the octet rule for every atom in the molecule? Why or why not?
Answer:
See explanation
Explanation:
The compound ClO2 has 19 valence electrons. ClO2 is a bent molecule with tetrahedral electron pair geometry but has two lone pairs of electrons. This is indicated by the presence of four electron pairs on the outermost shell of the central atom.
The molecule has an odd number of valence electrons, hence, it is generally regarded as a paramagnetic radical. None of the proposed Lewis structures for the molecule is satisfactory because none of them obeys the octet rule.
From the images attached, one can easily see that the electron dots around the oxygen and chlorine atoms does not satisfy the octet rule in all the resonance structures shown.
what is the hydronium ion concentration in a solution formed by combining 750mL of 0.10M NaOH with 250mL of 0.30 M HCl
Answer:
[tex][H^+]=1x10^{-7}M[/tex]
Explanation:
Hello.
In this case, since the reaction between sodium hydroxide and hydrochloric acid has a 1:1 mole ratio between them:
[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]
In order to compute the hydronium H⁺ concentration in the mixed volumes of the given solutions we first compute the moles of each reactant:
[tex]n_{NaOH}=0.750L*0.10mol/L=0.075mol\\\\n_{HCl}=0.250L*0.30mol/L=0.075mol[/tex]
As seen, since those amounts are the same, we infer all the acid and base are consumed so the pH is 7 because a neutral salt is produced, and the corresponding H⁺ concentration is:
[tex][H^+]=10^{-pH}=10^{-7}=1x10^{-7}M[/tex]
Best regards!
Suppose that Biuret reagent turns purple when it is added to an unknown substance. What can you conclude about the substance?
Answer:
the unknown substance is a protein
Explanation:
The biuret test is one of the tests for proteins. It can be used to detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed leading to the appearance of a violet color.
Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides. It involves the formation of a purple (violet) complex of Copper salts in alkaline solution.
Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein
A liquid has rhe following properties : one-phase,colorless,boils it varying temperature. Which of the following BEST describes this liquid
A.Solution
B.substance
C.suspension
D. Coarse mixture
Answer:
Solution
Explanation:
In science, the solution is a homogeneous mixture of two or more pure substances in proportional concentrations that can be continually varied up to what has been called the solubilization limit. The word solution is usually applicable to the fluid subatomic particle, but gaseous formulations are conceivable.
Which statements about mixture is FALSE?
A. The ingredients ofvthe mixture keep their physical properties
B. Mixture components can be separated
C. All mixtures are food or drink only
D. A mixture contains more than one ingredients
Calculate the number of grams of CuSO4 found in 3.29 mL of a 4.00 M CuSO4 solution. ______ grams CuSO4
Answer:
0.0132 g CuSO₄
General Formulas and Concepts:
[tex]\text{Molarity}=\frac{\text{moles of solute}}{\text{liters of solution}}[/tex]
Explanation:
Step 1: Define variables
3.29 mL
4.00 M CuSO₄
x g CuSO₄
Step 2: Define conversions
1000 mL = 1 L
Step 3: Solve
Convert mL to L: [tex]\text{3.29 mL}(\frac{\text{1 L}}{\text{1000 mL}} )[/tex] = 0.00329 LSubstitute: [tex]\text{4.00 M} \ CuSO_4=\frac{\text{x g} \ CuSO_4}{\text{0.00329 L}}[/tex]Multiply both sides by L: [tex]\text{0.01316} \ CuSO_4=\text{x g} \ CuSO_4[/tex]Rewrite: [tex]x = 0.01316 \ g \ CuSO_4[/tex]Step 4: Simplify
We are given 3 sig figs.
0.01316 g CuSO₄ ≈ 0.0132 g CuSO₄
Green light has a wavelength of 510 nm. What is the wavelength in meters?
Which set of procedures would be best to follow when separating a mixture of sand, salt, and water?
Answer:
Pour the mixture through a filter to separate the sand, then evaporate the liquid to separate the salt.
Explanation:
There are various methods used to separate single substances from a mixture. The method adopted depends upon the type of mixture and the ingredients used in it. According to the given question, the mixture comprises of sand, salt and water. Here, the first process will be the process of filtration. Through filtration, the salt-water solution and sand can be separated. Salt-water solution can be separated by the process of evaporation in which sat and water will be separated individually.
help pls
Which process of sedimentary rock formation occurs last?
cementation
compaction
deposition
erosion
Answer:
Compaction.
Explanation:
All the others are before this.
Please help fill in the blanks: The torso, which houses the apparatus consists of upper and lower cavities that are partitioned by the________.The upper cavity is called the _____ (or colloquially the chest) and is almost totally filled with the heart and lungs; the lower the cavity, the abdomen or belly, contains much of the ____ and other organs and glands.
Answer:
The torso, which houses the apparatus consists of upper and lower cavities that are partitioned by the diaphragm. The upper cavity is called the thoracic cavity (or colloquially the chest) and is almost totally filled with the heart and lungs; the lower the cavity, the abdomen or belly, contains much of the digestive tract and other organs and glands.
Explanation:
The torso, which houses the apparatus consists of upper and lower cavities that are partitioned by the diaphragm. The upper cavity is called the thoracic cavity (or colloquially the chest) and is almost totally filled with the heart and lungs. The thoracic cavity also contains the esophagus, the channel through which food is passed from the throat to the stomach.
The lower the cavity, the abdomen or belly, contains much of the digestive tract and other organs and glands such as the liver, the spleen, the kidneys, as well as the adrenal glands.
) What would be the effect on the molarity of the NaOH solution if some of the water evaporated from the Florence flask after the NaOH solution was standardized with the KHP
Answer:
The effect is the increasing of the molar concentration.
Explanation:
When you standarize a solution of NaOH with KHP you are establish its molar concentration (That is the amount of moles of NaOH per liter of solution).
If you evaporated some water of the solution, you are increasing its concentration because volume is decreasing doing the amount of moles per liter increasing.
How many atoms of Carbon are found on the PRODUCTS side?
In Fig 1-2, how should the length indicated by the arrow along the ruler be recorded?
Answer:
C. 0.35cm
Explanation:
The length indicated by the arrow along the ruler should recorded be recorded as "0.35cm".
This is correct because when counting the measurement on the ruler, the first line on the ruler is 0.1cm, the second line is 0.2cm, and so on. The spaces between each line is 0.05cm. So, the arrow is pointing on the space between 0.3cm and 0.4cm.
Therefore, 0.3cm + 0.05cm = 0.35cm.(answer).
A. In a separatory funnel containing ethyl acetate and 10% aqueous sodium bicarbonate (NaHCO3), which layer would contain the brominated aromatic compound?
Answer:
ethyl acetate layer
Explanation:
This question tests your knowledge of the principle of solvent extraction.
In solvent extraction, there is always an organic layer and an aqueous layer. The ethyl acetate is the organic layer while the sodium bicarbonate is the aqueous layer.
A brominated aromatic compound will be extracted into the organic layer (ethyl acetate layer).
How many valence electrons must a lithium atom lose to obtain a complete valence shell?
A. one
B. two
C. three
D. four
Answer:
C. three
Explanation:
A block of lead weighs 11.3 grams. How many atoms of lead are in this sample?
• Use 6.022 x 1023 mol
for Avogadro's number.
Answer:
To get the number of atoms in this sample, we first need the number of moles of lead in 11.3 grams
Number of moles of Lead:
Molar mass of lead = 207 grams / mol
Number of moles = given mass / molar mass
Number of moles = 11.3 / 207
Number of moles = 0.05 moles
Number of atoms of lead in 11.3 gram sample:
Number of atoms = Number of moles * avogadro's number
Number of atoms = 0.05 * 6.022 * 10²³
Number of atoms = 5 * 10⁻² * 10²³ * 6.022
Number of atoms = 30.11 * 10²¹
11.3 g block of lead contains 3.29×10²² atoms
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.022×10²³ atoms. Thus,
1 mole of lead = 6.022×10²³ atoms
Recall:
1 mole of lead = 207 g
Thus,
207 g of lead = 6.022×10²³ atomsWith the above information in mind, we can obtain the number of atoms in 11.3 g block of lead as illustrated below:
207 g of lead = 6.022×10²³ atoms
Therefore,
11.3 g of lead = (11.3 × 6.022×10²³) / 207
11.3 g of lead = 3.29×10²² atomsThus, 11.3 g block of lead contains 3.29×10²² atoms
Learn more: https://brainly.com/question/9758372
What is the pH of a solution made by mixing 0.050 mol of NaCN with enough water to make a liter of solution
Answer:
pH = 11
Explanation:
The equilibrium of a weak base as NaCN in water is:
NaCN(aq) + H₂O(l) ⇄ OH⁻(aq) + Na⁺(aq) + HCN(aq)
And kb, the equilibrium constant, is:
Kb = [OH⁻] [HCN] / [NaCN]
Where Kb of NaCN is 2.04x10⁻⁵
In the beginning, the [NaCN] is 0.050mol / L = 0.050M.
Both [OH⁻] and [HCN] are produced from this equilibrium, and its concentration is X, that is:
2.04x10⁻⁵ = [X] [X] / [0.050M]
1.02x10⁻⁶ = X²
X = 1x10⁻³ = [OH⁻]
As pOH = - log [OH⁻]
pOH = 3.00
And pH = 14 - pOH
pH = 11
Physical and chemical changes occur all around you every day. Read the story below and use the movable
highlighter pieces to highlight the physical changes in PURPLE and the chemical changes in ORANGE.
The physical changes are:
"blend up a banana smoothie instead"."cut a piece of bread in half"."I cracked two eggs and whipped them with a fork"."water had evaporated"."glass breaking"."Steam was rolling out"."broke off a piece"."the chocolate melted".The chemical changes are:
"the milk had soured"."was covered in brown spots"."it was completely tarnished"."plants were dying"."toast must be burning"."rusted bicycle".Changes of matterMatter can undergo 2 kinds of changes:
Physical changes: matter changes form but not its identity.Chemical changes: matter changes its identity due to a chemical reaction.Let's consider the following text.
When my alarm went off at 70'clock, I hit snooze" a few times then finally got out of bed with excitement for my morning bowl of cereal. I poured the cereal and milk into my bowl. But before I even drank it, I could tell from the smell that the milk had soured! So, I decided to blend up a banana smoothie instead. I took some ice out of the freezer and grabbed the only banana that we had in the kitchen, which was covered in brown spots. My grumbling stomach needed to be satisfied before school so I didn't really care.
Just as I was sitting down to drink my smoothie my little brother came bounding into the kitchen and asked, Would you make some eggs and toast for me for breakfast?
"Ugh, sure," I said. I cut a piece of bread in half and put it in the toaster, then I cracked two eggs and whipped them with a fork. I reached for one of my mother's copper cooking pans in the cabinet and saw that it was completely tarnished! I didn't want to be blamed for this, so I ran to tell my mother right away. As I ran out of the kitchen slipped on that banana peel and it smeared all over the floor. As I lay on the floor with the wind knocked from me, I noticed that our family's plants were dying and that some water had evaporated from our fish tank. I made a mental note to take care of these things after school.
Just as I regained my breath and stood up, I heard glass breaking upstairs and my mother shrieking. I ran up the stairs, breathing heavily now. Steam was rolling out from the open bathroom door. When the steam cleared, saw why my mother had been screaming. Before me was my older sister standing in the bathroom with purple hair. I inferred from the scene that my mother had dropped a glass when she first saw her look what your sister did to her hair my mother yelled furiously I decided that I needed to get out of the house immediately, this morning was a crazy one!
A distinct smell was waiting up the stairway and I realized that my brother's toast must be burning! When reached the kitchen, my brother was happily spreading butter on his very browned toast. "I like my toast really crispy!" he said.
"Good I can't handle any more chaos this morning! I exclaimed. I grabbed my backpack headed out into the foggy morning air, and hopped on my slightly rusted bicycle to ride to school. A few minutes into my ride, my stomach grumbled and I realized that I never got a chance to drink my banana smoothie. Luckily, I had stashed a chocolate bar in my backpack yesterday. "Yes! I thought as I stopped pedaling, grabbed the chocolate and broke off a piece. As the chocolate melted in my mouth, I knew that my day was bound to get better!
The physical changes are:
"blend up a banana smoothie instead"."cut a piece of bread in half"."I cracked two eggs and whipped them with a fork"."water had evaporated"."glass breaking"."Steam was rolling out"."broke off a piece"."the chocolate melted".The chemical changes are:
"the milk had soured"."was covered in brown spots"."it was completely tarnished"."plants were dying"."toast must be burning"."rusted bicycle".Learn more about physical and chemical changes here: https://brainly.com/question/17384175
What two types of elements make up an Ionic bond ?
Answer:
Metals and Non-metals
Explanation:
Why does sodium chloride form a crystal lattice
Answer:
Ions of opposite charge strongly attract each other; those of like charges repel. As a result ions in an ionic compound are arranged in a particular manner.
Explanation:
Google is smart
I Need Help Please ?
Answer:
Not sure dude goodluck
Explanation:
When you finish exercising, you are hot, tired, and sweating. After a bottle of juice, you feel a lot better. Which organ systems are working together in this scenario?
Answer:
Nervous and Excretory
Explanation:
The nervous system makes you thirsty. The integumentary system makes you sweat. the integumentary system is very similar to the Excretory system.
Nervous and Excretory systems are working together in this scenario.
The nervous system makes you thirsty. The integumentary system makes you sweat. the integumentary system is very similar to the Excretory system.
The blood flow increases, your brain is exposed to more oxygen and nutrients. Exercise also induces the release of beneficial proteins in the brain. Sweating cools the body when it becomes warm. When the body temperature rises, such as when exercising on a hot day, the dermal blood vessels dilate.The excretory system works with the endocrine system to help maintain homeostasis.Learn more:
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Please help will give brainliest _________________________________________________________________________________________________________________________________________
Answer:
What subject is this for?
Explanation:
what element has a higher ionization energy carbon or silicon
The table below gives the numbers of protons, electrons, and neutrons in four atoms.
Number of neutrons
Number of protons
19
Number of electrons
9
Atom
1
12
3
collo
18
10
9
9
9
10
4
19
Based on the table, which atom has a charge of -12
O 1
O 2
03
4
Answer:
THE ANSWER IS D UR WELCOME.
Explanation:
Fluorine is the first element in Group 17 of the periodic table. Bromine is the third element in the same group. Which statement is true of both
elements?
A. Both of their ions will have the same positive charge.
B. The charge on the ion formed by fluorine will be less than the charge on the bromine ion.
C. The charge on the ion formed by fluorine will be greater than the charge on the ion formed by bromine.
D. Both of their ions will have the same negative charge.
Answer:D. Both of their ions will have the same negative charge
Explanation: