Answer:
Hypothesis: IF a penny is dropped from a building, THEN it would kill a pedestrian below
Controls: Same building, Same distance
Independent variable: Penny
Dependent variable: Pedestrian's death
Conclusion: The hypothesis is rejected
Explanation:
- The hypothesis is a testable explanation to an observed problem or asked question. Based on the cientific question in this question, a possible hypothesis will be: IF a penny is dropped from a building, THEN it would kill a pedestrian below
- Independent variable is the variable that is changed or manipulated in an experiment. In this case, the PENNY is the independent variable
- Dependent variable is the variable that responds to the change made to the independent variable. It is the measured variable. In this case, the dependent variable is the DEATH OF PEDESTRIANS.
- Controls are those variables that is kept constant or unchanged throughout the experiment. The controls in this experiment are: Same building, Same distance of throw etc.
- The conclusion is whether the hypothesis is accepted or not depending on the result of the experiment conducted. In this case, the hypothesis will be rejected if the penny doesn't kill a pedestrian
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
Gases A and B are confined to a cylinder and piston and react to form product C. As the reaction occurs, the system loses 1189 J of heat to surroundings. The piston moves downward as the gases react to form a solid. As the volume of the gas decreases under the constant pressure of the atmosphere, the surroundings do 311 J of work on the system. What is the change in the internal energy of the system
Answer:
The change in the internal energy of the system -878 J
Explanation:
Given;
energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)
Work done on the system, W = -311 J (negative because work was done on the system)
change in internal energy of the system, Δ U = ?
First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).
ΔU = Q - W
ΔU = -1189 - (-311)
ΔU = -1189 + 311
ΔU = -878 J
Therefore, the change in the internal energy of the system -878 J
When aqueous solutions of AgNO3 and KI are mixed, AgI precipitates. The balanced net ionic equation is ________. When aqueous solutions of AgNO3 and KI are mixed, AgI precipitates. The balanced net ionic equation is ________. AgNO3 (aq) + KI (aq) → AgI (s) + KNO3 (aq) Ag+ (aq) + I- (aq) → AgI (s) AgNO3 (aq) + KI (aq) → AgI (aq) + KNO3 (s) Ag+ (aq) + NO3 - (aq) → AgNO3 (aq) Ag+ (aq) + NO3 - (aq) → AgNO3 (s)
Answer:
Ag⁺ (aq) + I¯ (aq) —> AgI (s)
Explanation:
We'll begin by writing the dissociation equation for aqueous AgNO₃ and KI.
Aqueous AgNO₃ and KI will dissociate in solution as follow:
AgNO₃ (aq) —> Ag⁺(aq) + NO₃¯ (aq)
KI (aq) —> K⁺(aq) + I¯(aq)
Aqueous AgNO₃ and KI will react as follow:
AgNO₃ (aq) + KI (aq) —>
Ag⁺(aq) + NO₃¯ (aq) + K⁺ (aq) + I¯(aq) —> AgI (s) + K⁺ (aq) + NO₃¯ (aq)
Cancel out the spectator ions (i.e ions that appears on both sides of the equation) to obtain the net ionic equation. The spectator ions are K⁺ and NO₃¯.
Thus, the net ionic equation is:
Ag⁺ (aq) + I¯ (aq) —> AgI (s)
The net ionic equation of aqueous solutions of [tex]AgNO_3[/tex] and [tex]KI[/tex] to form [tex]AgI[/tex] precipitates is: B. [tex]Ag^{+}_{(aq)} + I^{-}_{(aq)}[/tex] -----> [tex]AgI_{(s)}[/tex]
A balanced chemical equation can be defined as a chemical equation wherein the number of atoms on the reactant (left) side is equal to the number of atoms on the product (right) side.
This ultimately implies that, both the charge on each atom and sum of the masses of the chemical compounds or elements in a chemical equation are properly balanced.
An ion can be defined as an atom or molecules (group of atoms) that has lost or gained one or more of its valence electrons, thereby, making it have a net positive or negative electrical charge.
First of all, we would write the dissociation equation for aqueous solutions of [tex]AgNO_3[/tex] and [tex]KI[/tex]:
For [tex]AgNO_3[/tex]:
[tex]AgNO_3_{(aq)}[/tex] -----> [tex]Ag^{+}_{(aq)} + NO_{3}^{-}_{(aq)}[/tex]
For [tex]KI[/tex]:
[tex]KI_{(aq)}[/tex] -----> [tex]K^{+}_{(aq)} + I^{-}_{(aq)}[/tex]
Next, we would write a chemical equation for the reaction of aqueous solutions of [tex]AgNO_3[/tex] and [tex]KI[/tex]:
[tex]AgNO_3_{(aq)} + KI_{(aq)}[/tex] -----> [tex]Ag^{+}_{(aq)} + NO_{3}^{-}_{(aq)}[/tex] [tex]+ \;K^{+}_{(aq)} + I^{-}_{(aq)}[/tex] ----->[tex]AgI_{(s)} + K^{+}_{(aq)} + NO_{3}^{-}_{(aq)}[/tex]
Note: Spectator ions refers to the ions that exist as a reactant and a product in a chemical equation because they are unchanged by the chemical reaction.
In this chemical reaction, the spectator ions are:
[tex]K^+[/tex][tex]NO_{3}^{-}[/tex]Finally, in order to obtain the net ionic equation, we would cancel out the two (2) spectator ions:
[tex]Ag^{+}_{(aq)} + I^{-}_{(aq)}[/tex] -----> [tex]AgI_{(s)}[/tex]
Read more: https://brainly.com/question/13750908
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
) 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.
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?
1. In general, what is meant by the term chemical bond? Name and
describe the 3 principle types of chemical bonds.
Answer: The simplest and most common type is a single bond in which two atoms share two electrons. Other types include the double bond, the triple bond, one- and three-electron bonds, the three-center two-electron bond and three-center four-electron bond. ... Bonds within most organic compounds are described as covalent.
Explanation:
I Need Help Please ?
Answer:
Not sure dude goodluck
Explanation:
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 much acceleration does a 10 kg object have if pushed by a 75 N force?
a = 7.5 m/s²
Explanation:Hi there !
Newton's second law
F = m×a => a = F/m
1 N = 1kg·m/s²
a = (75kg.m/s²)/10kg
= 7.5 m/s²
Good luck !
What two types of elements make up an Ionic bond ?
Answer:
Metals and Non-metals
Explanation:
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]
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
help pls
Which process of sedimentary rock formation occurs last?
cementation
compaction
deposition
erosion
Answer:
Compaction.
Explanation:
All the others are before this.
4. What reagent would you predict to be in excess for reacting 7.50 mL of a 0.10M BaCl2 solution with 7.50 mL of 0.10M KIO3 solution
Answer : [tex]BaCl_2[/tex] reagent predict to be in excess.
Explanation : Given,
Concentration of [tex]BaCl_2[/tex] = 0.10 M
Volume of [tex]BaCl_2[/tex] = 7.50 mL = 0.0075 L (1 L = 1000 mL)
Concentration of [tex]KIO_3[/tex] = 0.10 M
Volume of [tex]KIO_3[/tex] = 7.50 mL = 0.0075 L
First we have to calculate the moles of [tex]BaCl_2[/tex] and [tex]KIO_3[/tex].
[tex]\text{Moles of }BaCl_2=\text{Concentration of }BaCl_2\times \text{Volume of }BaCl_2[/tex]
[tex]\text{Moles of }BaCl_2=0.10M\times 0.0075L=0.00075mol[/tex]
and,
[tex]\text{Moles of }KIO_3=\text{Concentration of }KIO_3\times \text{Volume of }KIO_3[/tex]
[tex]\text{Moles of }KIO_3=0.10M\times 0.0075L=0.00075mol[/tex]
Now we have to calculate the excess and limiting reagent.
The balanced equilibrium reaction will be:
[tex]BaCl_2+2KIO_3\rightleftharpoons Ba(IO_3)_2+2KCl [/tex]
From the balanced reaction we conclude that
As, 2 mole of [tex]KIO_3[/tex] react with 1 mole of [tex]BaCl_2[/tex]
So, 0.00075 moles of [tex]KIO_3[/tex] react with [tex]\frac{0.00075}{2}=0.000375[/tex] moles of [tex]BaCl_2[/tex]
From this we conclude that, [tex]BaCl_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]KIO_3[/tex] is a limiting reagent and it limits the formation of product.
Hence, [tex]BaCl_2[/tex] reagent predict to be in excess.
Which of the items below is a colloid?
a.fruit salad b.gelatin c.lacquer
Answer:
b. gelatin
Explanation:
a homogeneous noncrystalline consisting of large molecules or ultramicroscopic particles of one substance.
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
What does reflection mean?
Answer:
the throwing back by a body or surface of light, heat, or sound without absorbing it.
"the reflection of light"
Explanation:
i hope this helps
pencil has a density of 14.5 g/mL and a volume of 5 mL. Calculate the mass in grams.
Answer:
The answer is 72.5 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question we have
mass = 14.5 × 5
We have the final answer as
72.5 gHope this helps you
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.
which material should you use so that the area is cool in terms of temperture O asphalt O red bricks O concrete O soil O
Answer:
red bricks
Explanation:
right on edg 2020
Red bricks should you use so that the area is cool in terms of temperture. Therefore, option B is correct.
What are red bricks used for?Red bricks can be used in the construction of structures such as buildings, foundations, arches, pavement, and bridges. These can also be used for aesthetic purposes such as landscaping, face work, and a variety of other architectural purposes.
Traditional red bricks are saw to be more robust, and structures constructed with them are stronger than hollow block structures.Red brick can be warm, with rust or terracotta undertones. They could also be cool and more burgundy.
Thus, Red bricks should you use so that the area is cool in terms of temperture, option B is correct.
To learn more about the red bricks, follow the link;
https://brainly.com/question/14893671
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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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2) (3 pts) Convert 85 oF to oC.
Answer:
The answer will be 29.4˚C.
Explanation:
Using the formula 5(˚F-32)/9, plug in the numbers and you'll get 29.4˚C.
what element has a higher ionization energy carbon or silicon
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:
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).
9th grade science need help ASAP
Answer:
D
Explanation:
It is a solid everything that is a solid is heavier
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
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.