Answer:
Because Democritus or Liucipius cannot demonstrate or proof their ideas as they did not have any equipment or any research to prove the existence of atoms.
Explanation:
John Dalton, Democritus and Leucipius are some of the greatest scientist and scholars of the past.
Democritus originally proposed or gave the idea of the of the composition of the matter of indivisible and tiny particles. John Dalton is credited for the beginning of the modern atomic theory.
Democritus believed that a matter is made up of atoms that can move about empty spaces. They are small, indestructible, solid, indivisible and of different shapes and sizes. Democritus proposed his idea at that time as there were no scientific advancement or instruments to prove his ideas about atoms.
Later on when science and scientific processes were advanced, Dalton was able to prove and proceed on the atomic model theory.
Democritus cannot prove his ideas as there were no instruments or advance scientific processes and so people felt his ideas as illogical. His proposals were based on his ideas.
answers to student exploration : stoichometry (GIZMOS) WORTH 100 POINTS AND BRAINLIEST
4 Part of a human body system is pictured.
-Kidney
Ureter
Bladder
The main function of this system is to
F control reproduction
G transport oxygen
H produce hormones
J remove waste
Kidney in our body functions as a sieve in to remove wastes. Ureter, bladder and kidney as well are part of excretory system in animals. Hence, option J.
What is excretory system?Human body contains a group of organ systems to perform specific functions. Excretory system is an organ system for the excretion or removal of wastes after digestion form the body.
The main component of excretory system is kidney by which the wastes from the circulatory system is removed through urine. Ureter and bladder are extensions of kidney. After absorption of water and other nutrients remaining uric acid or urine is stored in the bladder to remove.
Kidney contains a number of sieve like structures called nephrons they are the filtering units of kidney.Nephrons are microscopic structural units of kidney by which wastes are filtered to produce urine and remove.
Therefore, all the given organs, kidney, ureter, bladder etc are part of excretory system and they plays a role in removing wastes from the body. Hence, option J is correct.
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please help :) thanks
Explanation:
it is the one you have selected because it is the only solid one
Samira has a son who is 24 months old. Her sister Paulina also has a son who is one and a half years old. Whose son is older? Explain how you know.
Answer:
the 24 month old
Explanation:
24 divided by the 12 months in a year is 2 and 2 compared to the 1 and a half is bigger
HELP ME QUICKLY!!
Use the portion of the periodic table shown below to answer the questions. (10 points)
A portion of the first three columns of the periodic table is shown. Column one from top to bottom reads 11 sodium 22.990, 19 potassium 39.098, and 37 rubidium 85.468. Column two reads 12 magnesium 24.305, 20 calcium 40.078, and 38 strontium 87.62. Column three reads 21 scandium 44.956 and 39 yttrium 88.906.
Part 1: Name two elements that have the same properties as potassium (K). (4 points)
Part 2: Determine the number of protons, electrons, and neutrons present in an atom of magnesium (Mg). Explain how you determined your answer using complete sentences. (6 points)
Your answer:
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Therefore, elements belonging to the same group have same physical and chemical properties.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Elements belonging to same column have same physical and chemical properties. 2 elements with same properties as K are rubidium and sodium.
Atomic number of magnesium is 12, means magnesium has 12 electrons, 12 protons. Mass number of Mg is 24. So, to find the number of neutrons we have to subtract 12 from 24, which is 12 neutrons.
Therefore, elements belonging to the same group have same physical and chemical properties.
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Morocco is separated into different territories of land with tribes often fighting for power to this day.
Answer:
umm whats the question??
Explanation:
A mineral has these 5 characteristics
2C3H7OH + 9O2 --> 6CO2 + 8H2O
Determine the number of grams of CO2 produced from the reaction of 5.55 moles of C3H7OH
733 g CO₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[RxN - Balanced] 2C₃H₇OH + 9O₂ → 6CO₂ + 8H₂O
[Given] 5.55 mol C₃H₇OH
Step 2: Identify Conversions
[RxN] 2 mol C₃H₇OH → 6 CO₂
Molar Mass of C - 12.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of CO₂ - 12.01 + 2(16.00) = 44.01 g/mol
Step 3: Stoichiometry
Set up conversion: [tex]\displaystyle 5.55 \ mol \ C_3H_7OH(\frac{6 \ mol \ CO_2}{2 \ mol \ C_3H_7OH})(\frac{44.01 \ g \ CO_2}{1 \ mol \ CO_2})[/tex]Multiply/Divide: [tex]\displaystyle 732.767 \ g \ CO_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
732.767 g CO₂ ≈ 733 g CO₂
Mass is a type of property that can be measured using a scale. Is mass considered a physical property or a chemical property? How do you know? It’s not a multiple choice
Answer:
Mass is an extensive physical property, it depends on the amount of matter being measured. It is physical because it can be measured without changing a substance's chemical identity.
i need help asap plz
Answer:
Incorrect
Explanation:
Sodium has 11 atoms
Answer:
[tex]incorrect......[/tex]
Study the chemical reaction.
4Fe + 3O2 → 2Fe2O3
What is the mole ratio between Fe and O2?
Answer: The mole ratio between Fe and [tex]O_2[/tex] is [tex]\frac{4Fe}{3O_2}[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The given balanced chemical equation is :
[tex]4Fe+3O_2\rightarrow 2Fe_2O_3[/tex]
Thus 4 moles of iron (Fe) reacts with 3 moles of oxygen gas [tex](O_2)[/tex] to give 2 moles of ferric oxide [tex](Fe_2O_3)[/tex]
The mole ratio between Fe and [tex]O_2[/tex] is [tex]\frac{4Fe}{3O_2}[/tex]
How many molecules are in one mole of H2SO4
Answer:
I think it is 20
Explanation:
Answer: 20, Hope this helped!
Explanation:
Write down a question about yeast fermentation that can be answered through scientific investigation.
Explanation:
Alcoholic fermentation converts one mole of glucose into two moles of ethanol and two moles of carbon dioxide, producing two moles of ATP in the process. The overall chemical formula for alcoholic fermentation is: C6H12O6 → 2 C2H5OH + 2CO
Answer:
1. If you leave yeast fermentation out for 3 days what happens?
2. If you put yeast fermentation out in the sun will it still work?
Explanation:
These can be answered through scientific investigation.
:)))))))
In the chemical reaction 2CO(g) + O2 —-> 2CO2 if you react 55.0g of oxygen gas you would expect to produce what volume of carbon dioxide at stp
Answer:
13mL of CO₂ are produced
Explanation:
Based on the chemical reaction:
2CO(g) + O₂(g) → 2CO₂(g)
Where 1 mole of O₂ in excess of CO produce 2 moles of CO₂}
Thus, to solve this problem we need to convert the mass of oxygen gas to moles and, using the chemical reaction we can find the moles of CO₂ and its volume at STP:
Moles O₂ -Molar mass: 32g/mol-
55g O₂ * (1mol / 32g) = 1.72 moles O₂
Moles CO₂:
1.72 moles O₂ * (2 moles CO₂ / 1mol O₂) = 3.44 moles CO₂
Volume:
PV = nRT
V = P / nRT
Where P is pressure = 1atm at STP
n are moles = 3.44 moles of CO₂
R is gas constant = 0.082atmL/molK
T is absolute temperature = 273.15K at STP
V = 1atm / 3.44mol*0.082atmL/molK*273.15K
V = 0.0130L = 13mL of CO₂ are produced
I NEED HELP BIG TIME PLZ HELP ME (ILL GIVE 40 POINTS) What is true of electrons? (3 points) a They are positively charged and located inside the nucleus. b They are positively charged and located outside the nucleus. c They are negatively charged and located inside the nucleus. d They are negatively charged and located outside the nucleus.
Answer:
d.
Explanation:
A student heats 4g of a blue compound, which reacts completely to produce 2.56 g of a white compound and an unknown amount of colorless gas. What is the mass of the gas?(you’ll get points and get marked as brainleist i think)
Answer:
1.44 g
Explanation:
We can solve this problem if we keep in mind the law of conservation of mass, which states that if 4 grams of a compound reacted completely, then the sum of the products has to be 4 grams as well.
(Reactants) 4 g = 2.56 g + x g (Products)We solve for x:
x= 4 - 2.56 = 1.44So the answer is 1.44 g.
Which of the following reactions is an example of a single replacement reaction?
Select one:
a. H2 + O2 --> H2O
b. CH4 + O2 --> CO2 + H2O
c. NaI + Br2 --> NaBr + I2
d. H2CO3 --> H2O + CO2
Answer:
C
Explanation:
Single replacement reactions is when only one element gets replaced / changed. This usually looks like this: A + BC = B + AC or A + BC = C + AB
Therefore, the number of reactants must be equal to the number of products, since no actual combinations / break ups are occurring.
Answers A and D are eliminated right away since the number of products don't equal the number of reactants.
Answer B is wrong because it does not show simply one element being replaced, instead, two compounds are being formed. It doesn't look like the example given.
Only answer C shows that one element is replaced:
The iodine is replaced with bromine to form NaBr + I2
The chemical equation NaI + Br₂ --> NaBr + I₂ is an example of single replacement reaction.
What is chemical equation?
Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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Which coefficients will balance this equation? *
Ag +
C2 >
AC2
Answer:
16Ag + 2C2 ---> 4 Ag4C
Explanation:
Ag + C2 ----> AgC2
The valence of Ag is one
Valence of Carbon is four
A balanced equation would be
16Ag + 2C2 ---> 4 Ag4C
4. Identify each substance in the following word equation as a reactant or a product
limestone heat lime + carbon dioxide.
5. What is the difference between an exothermic and endothermic reaction?
6. Sodium salicylate is made from carbon dioxide and sodium phenoxide. Identify each
of these substances as a reactant or a product.
Pllssssssssssssss
Explanation:
4. limestone heat lime + carbon dioxide
The reactants in this expression above is limestone
The products of the reaction is carbon dioxide and lime
Reactant is the species that gives the product and it is usually found on the left hand side of the expression.
The product is the substance on the right hand side of the expression that forms through the experiment.
Heat is used to facilitate the reaction.
5. An exothermic reaction is a reaction in which heat is given off.
An endothermic reaction is a reaction in which heat is absorbed in the process.
An exothermic reaction is always warmer after the reaction whereas an endothermic reaction is colder at the end of the reaction.
6. Sodium salicylate is made from carbon dioxide and sodium phenoxide.
The reactants are:
Carbon dioxide and sodium phenoxide
The product is:
Sodium salicylate
For the balanced equation shown below, if the reaction of 77.0 grams of CaCN2 produces 26.1 grams of NH3, what is the percent yield?
CaCN2+3H2O=>CaCO3+2NH3
%yield = 86.93%
Further explanationGiven
Reaction
CaCN₂+3H₂O=>CaCO₃+2NH₃
Required
The percent yield
Solution
mol CaCN₂(MW= 92 g/mol) :
= mass : MW
= 77 g : 92 g/mol
= 0.834
From equation, mol NH₃ :
= 2/1 x mol CaCN₂
= 2/1 x 0.834
= 1.668
Mass NH₃(theoretical):
= 1.668 mol x 18 g/mol
= 30.024 g
% yield = (actual/theoretical) x 100%
%yield = (26.1/30.024) x 100%
%yield = 86.93%
Use the drop Dow menus to select the names of the labeled structures
Answer:
theres no picture
Explanation:
Anything that has mass and takes up space
Answer:
true
Explanation:
Answer:
is matter
Explanation:
What is the density of an object with a mass of 34g and a volume of 13 cm3?
Answer:
d = 2.62 g/cm³
Explanation:
Given data:
Density of object = ?
Mass of object = 34 g
Volume of object = 13 cm³
Solution:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
By putting values,
d = 34 g/ 13 cm³
d = 2.62 g/cm³
What scientist explained the theory of atomic structure by relating it to the planetary model?
Answer: Rutherford
Explanation:
1. What is the theoretical
yield of C6H5Br in this reaction when 30.0 g of C6H6
reacts with excess Br2? If the
actual yield of C6H5Br was 56.7
g,
what
is
the
percent
yield?
Answer:
The theoretical yield in grams is 60.292 grams, and in moles the theoretical yield is 0.384. The percent yield is 94%.
Explanation:
The theoretical yield of bromobenzene is 60.3 grams and the percent yield of the reaction is 94.0%.
Explanation:
The percentage yield of the reaction is given by :[tex]Yield(\%)=\frac{\text{Actual or experimental yield}}{\text{Theoretcial yield}}\times 100[/tex]
Experimental yield is the amount of product produced after the carrying out the reaction practically.Theoretical yield is the amount of product calculated mathematically by using the amount of reactant.Given:
Mass of benzene = 30.0 g
The actual yield of bromobenzene = 56.7 g
To find:
Theoretical yield and percent yield of the reaction.
Solution:
Mass of benzene = 30.0 g
Moles of benzene =[tex]\frac{30.0 g}{78.11 g/mol}=0.384 mol[/tex]
[tex]C_6H_6+Br_2\rightarrow C_6H_5Br+HBr[/tex]
According to reaction, 1 mole of benzene gives 1 mole of bromobenzene, then 0.384 moles of benzene will give:
[tex]=\frac{1}{1}\times 0.384 mol=0.384 \text{mol of bromobenzene}[/tex]
Mass of 0.384 moles bromobenzene:
[tex]=0.384 mol\times 157.02g/mol=60.3 g[/tex]
The theoretical yield of bromobenzene = 60.3 g
The actual yield of bromobenzene = 56.7 g
The percent yield of the reaction:
[tex]Yield(\%)=\frac{56.7 g}{60.3 g}\times 100=94.0\%[/tex]
The theoretical yield of bromobenzene is 60.3 grams and the percent yield of the reaction is 94.0%.
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How many grams is 5.4x10 to the 23 molecules of al2o3?
Answer:
91.49 grams
Explanation:
No of molecules = no of moles × Avogadro's number
No of moles = No of molecules / Avogadro's number
Number of moles = 5.4×10^23/6.02×10^23
Number of moles = 0.897 moles of Al2O3
Number of moles = mass in gram / molar mass
Mass in gram = number of moles× molar mass
Mass in gram = 0.897× 102
91.49 grams