Answer:
b. 0.50 moles
Explanation:
To solve this problem we use Avogadro's number (6.023x10²³ atoms/mol).
By dividing the number of atoms (or molecules) by that number, we can calculate how many moles they represent.
3.01x10²³ atoms ÷ 6.023x10²³ atoms/mol = 0.50 molesSo the answer is option b. 0.50 moles.
Which of the following is a polar molecule?
A. A linear Carbon dioxide molecule (C02)
B. A carbon monoxide molecule (CO)
C. A calcium oxide molecule (CaO)
D. An oxygen molecule (02)
Answer:
B. A carbon monoxide molecule(CO)
Explanation:
CO is polar because oxygen is more electronegative than carbon, so it gives oxygen a partial negative charge and carbon and partial positive charge. This causes a net dipole moment. CO2 is linear with no net dipole moment because each C-O bond is equal and opposite to each other, so they equal 0, which makes them non polar.
How many carbon atoms are represented by the model below?
Answer:
3
Explanation:
when an electron gets closer to the nucleus does the attraction or repulsion grow weaker or stronger?
Answer:
Weaker
Explanation:
Since the charges on nucleus and electron are opposite in nature, an attractive force exists between them. It is true in generally, that when objects are made to move closer together in the direction of an attractive force, potential energy decreases (and increases whenever attracting objects are force to move apart).
Here, we are required to determine if the attraction or repulsion grow weaker or stronger.
When electrons get closer to the nucleus, the attraction grows stronger.First, we must establish scenarios when there can be attraction and ones where there can be repulsion.
By the law guiding electric charges; In electrical interactions:
Like poles repel while Unlike poles attract.
Also, in the atomic model; the nucleus is positively charged as it contains protons (+vely charged) and neutrons which are uncharged particles.Since the nucleus is positively charged and the electrons revolve round their orbit. Therefore, the force is an attraction force.As we all know that the force of attraction or of repulsion as the case may be is inversely proportional to the distance between the charged particles (the electrons and the nucleus in this case)When an electron gets closer to the nucleus, the distance between the electron and the nucleus reduces; and the force of attraction between the electron and the nucleus increases.Ultimately, when an electron gets closer to the nucleus, the attraction force will grow stronger due to the reduced distance between the electron and the nucleus.
Read more:
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How many hydrogen atoms are there in 2 molecules of C3H6?
Answer:
there are 12 hydrogen atoms in 2 molecules of C3H6
Explanation:
can we seperate naphthalene from sugar by filtration to obtain pure sugar?
Answer:
As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.
Sodium metal is added to a solution of magnesium chloride. Will a reaction occur? If so, what reaction will take place?
Please help me ASAP
What elements are present NaAl(SO4) in one of the components of baking powder?
Answer:
1 Sodium, 1 Aluminum (1 Sulfur, 4 Oxygen)
Explanation:
hope that helps
Give an example of a chemical reaction during which a single substance breaks
down. *
Answer:
2NaCl(l) => 2Na(s) + Cl₂(g)
Explanation:
Electrolysis of melt NaCl to form sodium (Na) metal and chlorine (Cl₂) gas.
This is a class of reaction called 'Decomposition Rxns'. For what it's worth, there are 6 distinct compound types that undergo breakdown by decomposition. The acronym C O A C H E can help remember them.
C - Carbonates => CaCO₃(s) => CaO + CO₂
O - Oxides of Metals => 2Fe₂O₃(s) => 4Fe°(s) + 3O₂(g)
A - Acids (Oxoacids) => H₂CO₃(aq) => CO₂(g) + H₂O(l)
C - Chlorates, Bromates & Iodates => 2KClO₃(s) => 2KCl(s) + 3O₂(g)
H - Hydroxides => Ca(OH)₂(s) => CaO(s) + H₂O(l)
E - Electrolysis => see above electrolysis of NaCl(l)
Answer:
2NaCl(l) => 2Na(s) + Cl₂(g)
Explanation:
Which combination of elements produce compounds with a large electronegativity difference and high conductivity?
Answer:
C. H2(g)
Explanation:
What are the reactants in the reaction? What are their properties? Perform a quick Internet search, if needed.
The reactants in this reaction are sodium and chlorine. Sodium is a soft, silvery-white metal that is highly reactive. Chlorine is a poisonous greenish-yellow gas that has an odor and combines readily with other elements.
This might be the exact question so you might wanna rephrase it but good luck! :)))
A reactant is a substance that undergoes change during a chemical reaction.
A reaction in a chemical experiment is which takes place when there are mixtures between two or more reactants.
There are about four types of reactions which are:
SynthesisDecompositionSingle replacementDouble replacementPlease note that your question is not complete, therefore, i would give you a general overview to help you.
Some examples of reactants include:
HydrogenSodiumChlorine, etcRead more here:
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at stp what is the volume of 5.35 moles of methane ch4
Answer:
22.4 L
Explanation:
help me fill this out please, i give brainliest
Answer:
Okay, Left top= waning gibbous
left second= new moon
left third= third quarter
left fourth= waxing crescent
right top= Waning crescent
right second= first quarter
right third= full moon
right fourth= Waxing gibbous
hope you do good :)
Answer:
first one waining gibbious
secound one waining crecent
third one new moon
fourth one first quarter
fithe one third quarter
sixth one full moon
sevnth one waxing crecent
eithe one waxing gibbious
Explanation:
A sample of pure radioactive isotope is left to decay. After 40.0 days, the 1 point
sample is placed in a mass spectrometer, and it is determined that only
25% of the original isotope remains. How long is the half-life?
Answer:
6 months and 1 day
Explanation:
Please help me this is my science final
Answer:
1.Winter
2.Autmn
3.Summer
4.Spring
I hope this helps!
Which of the following characteristics is NOT used to classify organisms into groups?
a.
nucleus or no nucleus
c.
color or no color
b.
autotroph or heterotroph
d.
unicellular or multicellular
Answer:
b
Explanation:
how many moles of sodium are present in a sample of sodium having a mass of 137 g? (molar mass is 23.0g)
Answer:
5.95 moles
Explanation:
No of moles = given mass / molar mass
No of moles = 137/23
= 5.95 moles
why water is not used as a thermometric substance
Answer:
Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.
Explanation:
Hope this help
Carbon dioxide is used by plants for ___?
Answer:
photosynthesis
Explanation:
that's the way plants feed themselves
Answer:
photosynthesis
Explanation:
I hope i helped
SOMEONE HELP PLS ILL GIVE BRAINLIEST AND 19 PT
Sample left = 6.25 g
The percentage = 6.25%
Further explanationGiven
t1/2 = half-life = 3.8 days
t = decay time = 15.2 days
No = initial sample = 100 g
Required
Nt = final sample left
The percentage
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
Input the value :
[tex]\tt N_t=100.\dfrac{1}{2}^{15.2/3.8}\\\\N_t=100.\dfrac{1}{2}^4\\\\N_t=6.25~g[/tex]
The percentage : Nt/No
6.25 : 100 = 6.25%
help me please with my science test questions 5 and 6
Answer:
5. Element J has the highest atomic number
6. Elements G and L have the same number of electrons in their outermost shell.
Explanation:
The periodic table of elements is a table which shows the arrangement of the elements in the order of increasing atomic number. Starting from the topmost left-hand side of the table where the element with the least atomic number is placed, and going across the table from left to right and down to the lowest point to the right of the table, where the element with the highest atomic number is located, the atomic number of elements progressively increases.
Looking at the table, it can be seen that the element J is found at the lowest point to the right of the table. Therefore, element J has the highest atomic atomic number.
6. In the periodic table, elements are arranged into groups and periods. The groups are the columns while the periods are the rows. Elements in the same column or group have the same number of electrons in their outermost shell. Therefore, element G and L have the same number of electrons in their outermost shell.
Please help quick
1) How much heat does 23.0 g of water absorb as its temperature increases from 25.4 °C to 42.8 °C?
2) A sample of unknown metal has a mass of 120.7 g. As the sample cools from 90.5 °C to 25.7 °C, it releases 7020 J of energy. What is the specific heat of the sample?
Answer:
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C
7020 J = -7821.36 g.°C × c
c = 7020 J / -7821.36 g.°C
c = 0.898 J/g.°C
Negative sign shows heat is released.
What is the percent composition of nitrogen in N 2 O
Answer:
63.6%
Explanation:
The given compound is:
N₂O;
The problem here is to find the percent composition of nitrogen in the compound.
First find the molar mass of the compound:
Molar mass of N₂O = 2(14) + 16 = 44g/mol
So;
Percentage composition of Nitrogen = [tex]\frac{2 x 14}{44}[/tex] x 100 = 63.6%
what is a displacement reactions
A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal.
A + BC → AC + B
The above equation exists when A is more reactive than B.
A and B have to be either:
Halogens where C indicates a cation.
Different metals wherein C indicates an anion.
[tex]\textsf{what is a displacement reactions? }[/tex]
Answer:[tex]\large \underbrace{ \underline{ \sf Displacement \: reaction}}[/tex]
The reaction in which more reactive element replace a less reactive element from its compound is called displacement reaction.
Ex:-
[tex]\bold{\large Zn+HCl \longrightarrow ZnCl_2+H_2}[/tex]
calculate the number of particles in each of the following a. 18 gram of O2 molecules b. 0.1 mole of Calcium atomic
Answer:
3.39 x 10²³ particles
6.02 x 10²²particles
Explanation:
The problem here entails we find the number of particles in the given substances.
From the mole concept;
1 mole of a substance contains 6.02 x 10²³ particles
a. 18g of O₂;
We first find the number of moles of this substance first;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of O₂ = 2(16) = 32g/mol
Number of moles = [tex]\frac{18}{32}[/tex] = 0.56mole
So;
1 mole of a substance contains 6.02 x 10²³ particles
0.56 mole of O₂ will contain 0.56 x 6.02 x 10²³ particles
= 3.39 x 10²³ particles
b. 0.1mole of calcium atom:
1 mole of a substance contains 6.02 x 10²³ particles
0.1 mole of the substance will contain 0.1 x 6.02 x 10²³ particles
= 6.02 x 10²²particles
please help!! I’m really confused because it’s actually supposed to be called occluded front but the definition is true.
"30 mph north" is an example of:
O velocity
speed
distance
O displacement
Answer:
distance velocity displacement, all three
Explanation:
pls answer i need it now!! I will give brainliest to the best answer!!
Answer:
sample 2
Explanation:
hope this helps
Stephanie the Skydiver has a mass of 48kg, what is the force that she
exerts as she is falling to the ground?
Answer:
470.4N
Explanation:
Given parameters:
Mass of Stephanie = 48kg
Unknown:
Force she exerts while falling to the ground = ?
Solution:
The force she exerts is her weight;
Weight = mass x acceleration due to gravity
Now insert the parameters ands solve ;
Weight = 48 x 9.8 = 470.4N
Does it take shorter or longer time to travel when the velocity is low?
Answer:
yes
explanation:
yes because when the velocity is low, all the energy is low and nothing can't do nothing without energy
Which of these is a characteristic of science? (5 points) Question 1 options: 1) It cannot be reproduced by any scientist. 2) It cannot be changed by new knowledge. 3) It is based on empirical evidence. 4) It is guided by a set of values.
Answer:
3
Explanation:
It is based on empirical evidence
The characteristic of science is that it is based on empirical evidences comprising of a hypothesis.
What is a hypothesis?
Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
Learn more about hypothesis,here:
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