Which of the following is considered a contact force?
Group of answer choices
friction between an object and chair
the force between two magnets
the force between two charged particles
the gravitational pull of a planet
Answer:
☑ Friction between an object and chair
☐ The force between two magnets
☐ The force between two charged particles
☐ The gravitational pull of a planet
please answer this i need this:(
Answer:
need what?? I would love to help though!
Answer:
Explanation:
IN order for us to help you, we would like to know the question.
An unknown element (Uk) has three isotopes, as presented in
the table below. One of the percentage values is missing.
After calculating the missing percent abundance (%).
determine the average atomic mass of Uk.
Enter your answer to the hundredths place.
Percent
Abundance
(%)
Uk-66 65.994 58.00
Isotope Mass
Notation (amu)
Uk-69 68.958
Uk-71 70.975
10.00
?
The average atomic mass of the element, Uk is 67.44 amu.
What is the average atomic mass of the element, Uk?The average atomic mass of the element Uk is determined from the sum of the isotopic masses of the isotopes of the element and their relative abundances.
average atomic mass = sum of (isotopic mass * relative abundance) of the isotopesThe isotopic masses and relative abundance of the isotopes are given below:
Isotope:Uk-66; Isotopic mass = 65.994; relative abundance = 58.00%
Isotope:Uk-69; Isotopic mass = 68.958; relative abundance = ?
Isotope:Uk-71; Isotopic mass = 70.975; relative abundance = 10.00%
Relative abundance of Uk-69 = 100% - (58 + 10)% = 32%
The average atomic mass of Uk = (65.994 * 58.00%) + (68.958 * 32%) + (70.975 * 10.00%)
The average atomic mass of Uk = 67.44 amu
In conclusion, the average atomic mass of an element is obtained from the of the isotopic masses of the isotopes of the element and their relative abundances.
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What are the spectator ions in the reaction between KCl (aq) and AgNO3 (aq)?
A) K+ and Ag+
B) Ag+ and Cl-
C) K+ and NO3
-
D) Ag+ and NO3
Answer:
K^+ and NO3-
Explanation:
The correct answer to the question is Option C. K⁺ and NO₃¯
Spectator ions are ions that remains unchanged in a reaction i.e they can be seen in the reactants and products of a particular reaction.
To obtain the spectator ions in the reaction between KCl (aq) and AgNO₃ (aq), we shall write the ionic equation. This is illustrated below:
KCl (aq) —> K⁺(aq) + Cl¯(aq)
AgNO₃ (aq) —> Ag⁺(aq) + NO₃¯(aq)
KCl (aq) + AgNO₃ (aq) —>
K⁺(aq) + Cl¯(aq) + Ag⁺(aq) + NO₃¯(aq) —> AgCl(s) + K⁺(aq) + NO₃¯(aq)
From the ionic above, we can see that K⁺ and NO₃¯ appears on both side of the equation.
Therefore, K⁺ and NO₃¯ are the spectator ions.
Thus, Option C. K⁺ and NO₃¯ gives the correct answer to the question.
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A sample of oxygen has a volume of 25.00 mL with a pressure of 2.0 atm. What pressure (in atm) will the sample of O2 gas occupy at 100.0 mL?
Answer:
0.5 atmExplanation:
The final pressure can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new pressure
[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]
From the question we have
[tex]P_2 = \frac{25 \times 2}{100} = \frac{50}{100} = \frac{1}{2} \\ [/tex]
We have the final answer as
0.5 atmHope this helps you
Which of the following are products of the reaction listed? Zn + 2HCI
ZnCl2 + H2
H2
НСІ
ZnCl2
Zn
Answer:
ZnCl2
H2
Explanation:
The products of the given reaction is:
ZnCl₂ and H₂
The two species are the products of the chemical combination
This reaction is a single displacement reactionBecause Zn is more reactive, it displaces hydrogen from the acidThis forms a hydrogen gasWe know this because Zn is higher in the activity series.How many grams of molybdenum(Mo) are in 2.68E24 atoms of Mo?
427 g Mo
General Formulas and Concepts:Chemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right Explanation:Step 1: Define
2.68E24 atoms Mo or 2.68 × 10²⁴ atoms Mo
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of Mo - 95.94 g/mol
Step 3: Convert
[tex]2.68 \cdot 10^{24} \ atoms \ Mo(\frac{1 \ mol \ Mo}{6.022 \cdot 10^{23} \ atoms \ Mo} )(\frac{95.94 \ g \ Mo}{1 \ mol \ Mo} )[/tex] = 426.966 g Mo
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
426.966 g Mo ≈ 427 g Mo
Which plate, oceanic or continental, must be more dense? How do you know
this?
Answer:
Oceanic crust is not only thinner and denser than continental crust, and it is also much younger than it and has a different chemical composition. When magma from the mantle of the earth finds a way up, it comes into contact with water that cools it down quickly
Which explains the change in ionization energy that occurs between removing
the first and second electrons from an
atom?
O The ionization energy decreases because the ratio of the protons to electrons increases.
O The ionization energy increases because the ratio of the protons to electrons increases.
O The ionization
energy decreases because the ratio of the protons to electrons decreases.
O The ionization energy increases because the ratio of the protons to electrons decreases.
The ionization energy increases as the ration of protons to electrons increases.
On the periodic table, as we move from left to right through a period, the initial ionization energy rises. This is due to the outermost electron becoming more closely bound to the nucleus as the nuclear charge increases.
Ionization energy - the energy needed to remove an electron from a gaseous atom, is the one that best exemplifies periodic behavior.
The energy needed to remove each additional electron from an atom grows gradually, with the removal of an electron from a filled inner shell causing a significant increase.
A stable atom becomes electrically imperfect or imbalanced if we remove one of its electrons. In other words, the nucleus's protons (positive charges) outnumber its electrons (negative charges). It is a positive ion because the atom has a plus-one charge after losing an electron.
Therefore on removing the second electron more ionization energy will be required than first. So option D is correct.
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why fe2o3 is called ferric oxide
Answer:
it contains O3, therefore making it an oxide
Answer:
iron (11) oxide
Explanation:
18 pointssssssssssss help plz :)
HELP ME PLEASE ASAP FOR MY FINALSS!!!!!
Plant Leaf Model
Students read the following information about photosynthesis in their science textbook:
Plants use photosynthesis to make food
Animals get their food from plants
Photosynthesis produces a compound needed for respiration
The students want to build a simple model to represent photosynthesis in plants. They start with the materials shown below that they cut out of paper and label.
image c221f83634f54faf8522f256b7fce5a6
Which list BEST identifies how the arrows should be arranged around the paper leaf in the model to represent the movement of matter and flow of energy during photosynthesis?
A.
image 61ded7b213b443e08be3f457b66a7c02
B.
image 59241613e289486295f9fa893d4748e0
C.
image 4d21a3beee3a4555aed99677ecd74b7c
D.
image 66f376a76bb8401caffba053d6cf8973
Calculate the amount of heat required to completely sublime 96.0 gg of solid dry ice (CO2)(CO2) at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 kJ/molkJ/mol. Express your answer in kilojoules.
Answer:
The correct answer is 70.41 kJ ≅ 70.4 kJ
Explanation:
The heat required to sublimate the solid at its sublimation temperature is calculated by using the following formula:
heat = ΔHs x moles of substance
Where ΔHs is the heat of sublimation, which is known (32.3 kJ/mol).
So, we have to calculate the moles of substance. For this, we can divide the mass of substance by the molecular weight of substance (CO₂):
mass CO₂ = 96.0 g
molecular weight CO₂ = (12 g/mol x 1) + (16 g/mol x 2) = 44 g/mol
⇒ moles of CO₂ = mass CO₂/molecular weight CO₂ = (96.0 g)/(44 g/mol) = 2.18 moles
Finally, we use the first formula to calculate the heat:
heat = ΔHs x moles = 32.3 kJ/mol x 2.18 mol = 70.41 kJ ≅ 70.4 kJ
Which of the following has kinetic energy?
Wind blowing at 3 km/h
A fully stretched elastic band
A boulder sitting on top of a hill
An unused battery
Answer:
wind blowing
Explanation:
"Wind is energy in motion—kinetic energy"
Answer: Wind Blowing
Explanation:
A student is doing an experiment that stoichiometry says should produce 34.6 grams of product. The student actually makes 25.2 grams. What is the students percent yield?
Percent yield of a reaction is the ratio of actual yield to the theoretical yield multiplied by 100. The percent yield of the reaction with the theoretical yield 34.6 g and actual yield of 25.2 g is 72.8%.
What is percent yield ?Percent yield is used compare the actual yield and theoretical yield of a reaction. It is the ratio of actual yield to the theoretical yield multiplied by 100.
Theoretical yield of a reaction is determined from the balanced chemical equation of the reaction. The actual yield or experimental value must vary from the stoichiometric expectation.
Given the theoretical yield = 34.6 g
actual yield = 25.2 g
percent yield = actual yield/ theoretical yield × 100
= 25.2 g/ 34.6 g × 100 = 72.8 %
Therefore, the percent yield of the reaction is 72.8 %.
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The higher the pH, the less acidic the solution
Answer:
yh thats true lol, ty for that very interesting fact
If the pH is higher the concentration of hydrogen ions becomes less and the solution becomes less acidic.
As the pH becomes lower, the concentration of hydrogen ions becomes greater, and the solution becomes more acidic.
HOPE IT'S HELPFUL : )
How many molecules are there in 39 grams of water
Answer:
I think its 117
Explanation:
H20
2*39 (hydrogens)
78
78+39(oxygens)
117
he number-average molecular weight of a polypropylene is 1,000,000 g/mol. Compute the degree of polymerization.
Answer:
The answer is "23765.4"
Explanation:
Motor weight average number [tex](\bar{M_n}) = 1000000 \frac{g}{mol}[/tex]
Poly condensation degree dependent on the average number of molecular weights is as follows:
[tex]DP_n = \frac{\text{Mol.Wt Number Medium}}{\text{Monomer Unit Mol.Wt}}[/tex]
All monomer module, in this case, is propylene
Sunrise. Unit Wt = Mol. Propylene weight
[tex]= \ Mol. \ Wt \ of \ C_3H_6\\\\= 3 \times 12.01 +6 \times 1.008 \ \ \frac{g}{mol}\\\\= 42.078 \frac{g}{mol}\\\\[/tex]
[tex]DP_n = \frac{1000000}{42.078}\\\\[/tex]
[tex]=23765.4[/tex]
6CO2 + 6H2O → C6H12O6 + 6O2
Is this a balanced equation? Then if not, please balance the equation.
Identify each atom and number of atoms
What are the reactants and what are the products?
Is this equation in Dynamic Equilibrium?
Is this equation Endothermic or Exothermic?
Answer:
6CO2 + 6H2O → C6H12O6 + 6O2 is a balanced equation
Explanation:
Carbon, Oxygen, Hydrogen
Reactants are carbon dioxide and water, products are glucose and oxygen
Dynamic Equilibrium I have no idea about (soz)
I believe this might be endothermic
Jorge has an unknown mineral. The mineral has a mass of 21 grams and has a volume of 3cm3. Calculate density and find his unknown material
Answer:
7g/cm³
Explanation:
Given parameters:
Mass of the mineral = 21g
Volume = 3cm³
Unknown:
Density of the mineral = ?
Solution:
Density of a substance is the mass per unit volume of the substance.
Density = [tex]\frac{mass}{volume}[/tex]
Now insert the given parameters and solve;
Density = [tex]\frac{21}{3}[/tex] = 7g/cm³
The mineral with a density of 7g/cm³ is Galena, an ore of lead.
rock with a mass of 70 grams is dropped into a graduated cylinder with 30 mL of water. The water level rose. Whats the density of the rock in g/mL.
The density of the rock in g/mL : 14 g/ml
Complete question :
A rock with a mass of 70 grams is dropped into a graduated cylinder with 30 mL of water in it. The water level rose to 35 mL calculate the density of the rock in g/mL
Further explanationDensity is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
ρ = density
m = mass
v = volume
mass of rock = 70 g
Volume of the rock : 35 - 30 = 5 ml
So the density :
[tex]\tt \rho=\dfrac{70}{5}\\\\\rho=14~g/ml[/tex]
Balance the following DECOMPOSITION chemical reaction:
___Al2O3 (s)--> ___ Al (s) + ____ O2 (g)
a
3, 2, 4
b
4, 3, 2
c
4, 2, 3
d
2, 4, 3
Answer:
d 2,4,3
Explanation:
2 Al2O3 ----> 4 Al + 3 O2
To solve such this we must know the concept of redox reaction. Therefore, the correct option is option D. the balanced decomposition chemical reaction can be given as
2 Al[tex]_2[/tex]O[tex]_3[/tex] [tex]\rightarrow[/tex] 4 Al + 3 O[tex]_2[/tex]
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
Decomposition reaction is a reaction which one reactant breaks down into two or more products in presence of energy in the form of heat or electricity. The balanced decomposition chemical reaction can be given as
2 Al[tex]_2[/tex]O[tex]_3[/tex] [tex]\rightarrow[/tex] 4 Al + 3 O[tex]_2[/tex]
Therefore, the correct option is option D. the balanced decomposition chemical reaction can be given as
2 Al[tex]_2[/tex]O[tex]_3[/tex] [tex]\rightarrow[/tex] 4 Al + 3 O[tex]_2[/tex]
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PLEASE HELP
This picture represents a model of:
Question 5 options:
Oxygen
Calcium
Boron
Neon
Answer:
The picture represents oxygen.
Explanation:
There are two notable ways you can figure this out:
1) Since there are eight protons, you can automatically know that you are looking for an element with an atomic number of 8. This is because the atomic number is the number of protons in an atom.
2) You can also note the number of electrons on the outer shell. These are called valence electrons. You can then see that the element has 6 valence electrons. Beginning with Lithium on the periodic table and count by ones going from left to right in period 2 of the periodic table until you get to 6. What element is that? It is indeed oxygen.
Answer:
Oxygen
Explanation:
Neons contain 8 protons and 10 ELECTRONS
Boron contains 5 protons an 5 electrons
calcium contains 20 electrons an 0 protons
What is the answer? Please
Answer:
Carbon Dioxide
Explanation:
Because plants take in Carbon Dioxide, then let out Oxygen
Chlorite anion was exposed to strong radiation and had 2 successive electrons removed, creating a chlorite cation. What is the molecular geometry on this chlorite cation?
Answer:
bent
Explanation:
The chlorite ion has been pictured in the image attached with its two main resonance contributors.
The ion has four regions of electron density as shown. On the basis of the VSEPR theory, we expect a tetrahedral geometry.
However, the ion is bent due to the effect of the lone pairs on chlorine which is the central atom in the ion. This distorts the bond angle of the ion hence the ion has a bent molecular geometry.
what would be the reaction mechanism?
Answer:
ch2coo3 is the reaction of mechanism
Sodium carbonate reacts with silver nitrate according to the following balanced equation: Na2CO3 (s) + 2 AgNO3 (aq) → Ag2CO3 (s) + 2 NaNO3 (9) If 3.60 g of Na2CO3 is allowed to react with 5.14 g of AgNO3, what mass of Na2CO3 will remain at the end of the reaction?
a) 2.01 g
b) 1.54 g
c) 0.423 g
d) 0.0150 g
e) 0g
Answer:
a) 2.01 g
Explanation:
Na₂CO₃ (s) + 2AgNO₃ (aq) → Ag₂CO₃ (s) + 2NaNO₃First we convert 0.0302 mol AgNO₃ to Na₂CO₃ moles, in order to calculate how many Na₂CO₃ moles reacted:
0.0302 mol AgNO₃ * [tex]\frac{1molNa_2CO_3}{2molAgNO_3}[/tex] = 0.0151 mol Na₂CO₃So the remaining Na₂CO₃ moles are:
0.0340 - 0.0151 = 0.0189 moles Na₂CO₃Finally we convert Na₂CO₃ moles into grams, using its molar mass:
0.0189 moles Na₂CO₃ * 106 g/mol = 2.003 g Na₂CO₃The closest answer is option a).
15.How can a pure sample of barium sulphate be otained from barium carbonate?
Answer:
Barium carbonate powder is stirred add pulp in the entry, the vitriol that the adds solubility then reaction that makes the transition is filtered and is obtained the barium sulfate filter cake and liquid after the transition.
Calculate the molar mass of a 2.89 g gas at 346 ml, a temperature of 28.3 degrees Celsius, and a pressure of 760 mmHg.
The molar mass of gas = 206.36 g/mol
Further explanationIn general, the gas equation can be written
[tex]\large{\boxed{\bold{PV=nRT}}}[/tex]
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.082 l.atm / mol K
T = temperature, Kelvin
mass (m)= 2.89 g
volume(V) = 346 ml = 0.346 L
T = 28.3 C + 273 = 301.3 K
P = 760 mmHg=1 atm
The molar mass (M) :
[tex]\tt PV=\dfrac{m}{M}RT\\\\M=\dfrac{mRT}{PV}\\\\M=\dfrac{2.89\times 0.082\times 301.3}{1\times 0.346}\\\\M=206.36~g/mol[/tex]
Give the name of one or more polysaccharides that matches each of the following descriptions:
a. not digestible by humans
b. the storage form of carbohydrates in plants
C. contains only oc (1-4)-glycosidic bonds
d. the most highly branched polysaccharide
Answer:
A Cellulose not digested by humans.
b. the storage form of carbohydrates in plants is starch
C amylose contains 1-4 glycosidic bond
D Glycogen and starch are highly branched polysaccharides.
Explanation:
The name of one or more polysaccharides that matches each of the following descriptions are given as: a. not digestible by humans- cellulose, b. the storage form of carbohydrates in plants-starch, c. contains only oc (1-4)-glycosidic bonds-amylose, d. the most highly branched polysaccharide-glycogen.
Monosaccharides—repeated sugar units—are joined by glycosidic linkages to form polysaccharides, which are large, complex carbohydrates. They are polymers consisting of hundreds of monosaccharide molecules or even thousands of them.
a. Humans cannot digest the carbohydrate known as cellulose. It is a part of the structure of plant cell walls.
b. The plant stores carbohydrates in the form of starch. It functions as a store of energy and is made up of the molecules amylose and amylopectin.
c. A polysaccharide called amylose only has linkages that are (1-4)-glycosidic. It consists of glucose units joined together by (1-4)-glycosidic linkages, and is a linear polymer.
d. The polysaccharide that has the most branches is glycogen. In particular, the liver and muscles, it is the most prevalent form of carbohydrate storage in both animals and people.
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