Answer:
A. Elements are pure substances.
Explanation:
Out of all four answers A would be best. Hope this helps.
Answer:
B
Explanation:
I think all options can define element in one form or another but an element is characterized by the atomic number it has i.e you will know it's Carbon due to it's number of protons, neutrons and/or electrons.
20
How do you determine the number of barium atoms in the formula below?
4Ba(OH)2
F
# of Ba atoms = coefficient 4 + subscript 1 = 5
G
# of Ba atoms = coefficient 4 X subscript 1 = 4
H
# of Ba atoms = subscript 4 X coefficient 2 = 6
# of Ba atoms coefficient 1 + subscript 1 = 2
J
Answer:
G is correct option:
# of Ba atoms = coefficient 4 × subscript 1= 4
Explanation:
Formula:
4Ba(OH)₂
G is correct option:
# of Ba atoms = coefficient 4 × subscript 1= 4
Because there are only 4 atoms of Ba in given formula.
Ba(OH)₂ contain one atom of Ba while in question there are 4 moles of Ba(OH)₂ present thus total 4×1 = 4 atoms of Ba present.
Other options are incorrect. Because,
F:
# of Ba atoms = coefficient 4 + subscript 1 = 5
This shows given formula contain 5 Ba atoms. So it is incorrect.
H:
# of Ba atoms = subscript 4 × coefficient 2 = 6
This shows that subscript is 4 which is incorrect because coefficient is 4 and subscript is 1.
j:
# of Ba atoms = subscript 1 + coefficient 1 = 2
This option shows that subscript is one which is correct but coefficient is incorrect. The coefficient of Ba is 4 and coefficient is always multiply with subscript not added. So this option is also incorrect.
All good experiments should be...
Ok
A plant part that contains a tiny new plant, or embryo
seed
spore
root
flower
A scientist plans to find out the cause of decrease in bird population in a location. He interviews 50 people who work in the local oil mine and 45 of them believe that the mine does not affect the birds. The scientist concludes that 90 percent of people in the location believe that the local oil mine does not cause decrease in bird population. Why is the scientist's conclusion most likely unreliable? (2 points)
Group of answer choices
a. the results of the investigation cannot be repeated
b. the source of information could be biased
c. bird population cannot be measured accurately
d. the investigation is done by only one person
Answer:
Explanation:
Which is not the name of a family on the periodic table
a) Halogens
b) Noble Gases
c) Alkali Earth Metals
d) Actinides
;
Explanation: Look at the scrrn shot and you can see what is on there or not. :)))))
Actinides are not the name of the family of the periodic table.
Explanation:
In the modern periodic table :
Elements are arranged on the basis of their atomic numbersThere are 18 groups(vertical groups) and 7 periods (horizontal rows)Groups are also called families of the periodic table.Metals are present from the middle to the left-hand side of the periodic tableNonmetals are present on the upper right-hand side of the periodic tableMetalloids divide the periodic table in a zig-zag line with nonmetals on the right and metals on the left.The alkali metals are present under group 1The alkaline earth metals are present under group 2The noble gases are present under group 18The halogens are present under group 17The elements in separate two horizontal rows in the bottom are lanthanides and actinides.So, from this, we can conclude that actinides are not the name of the family of the periodic table.
Learn more about the periodic table:
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Which is denser a liquid or solid why?
Answer:
Liquids are usually less dense than solids but more dense than air. Temperature can change a liquid's density. For example, increasing the temperature of water causes the molecules to spread farther apart. The farther apart the molecules are, the less dense the water is.
Answer:
Solids are usually much more dense than liquids and gases, but not always.
Explanation:
Mercury, a metallic element that is a liquid at room temperature, is denser than many solids. Aerogel, a very unusual human-made solid, is about 500 times less dense than wate
Item 4
Which statement is one of the three parts of cell theory?
Cell organelles can be membrane-bound or not membrane-bound.
Cells make up tissues, tissues make up organs, organs make up systems, systems make up organisms.
The smallest living things are single cells, and cells are the functional units of multicellular organisms.
There are three types of cells, prokaryotic, eukaryotic plant, and eukaryotic animal.
Violet light has a wavelength of 4.50 x 10-12 m. What is the frequency?*
3 points
1.5 x10^20 1/s
0.0135 1/s
6.77x10^19 1/5
3x10^8 1/s
Green light has a frequency of 6.73 x 1014 1/s. What is the wavelength?*
3 points
2.24x10^6 m
4.46x10^-7 m
2.02 x 10^23 m.
4.95 x 10^-24 m
3 points
What is the energy (Joules) of violet light with a frequency = 3.43 x 10^14
1/s? *
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
2.27 x 10^-19 J
Answer:
Frequency = 6.67x10¹⁹ s⁻¹
Wavelength = 4.46x10⁻⁷m
e = 2.27x10⁻¹⁹J
Explanation:
To convert frequency to wavelength and vice versa we use the equation:
Wavelength = Speed of light / Frequency
Speed ligth is 3x10⁸m/s
For a wavelength of 4.50x10⁻¹²m:
4.50x10⁻¹²m = 3x10⁸m/s / Frequency
Frequency = 3x10⁸m/s / 4.5x10⁻¹²m
Frequency = 6.67x10¹⁹ s⁻¹For a frequency of 6.73x10¹⁴s⁻¹:
Wavelength = 3x10⁸m/s / 6.73x10¹⁴s⁻¹
Wavelength = 4.46x10⁻⁷mAnd energy, e, from frequency, is obtained as follows:
e = h ₓ frequency
Where h is Planck's constant, 6.626x10⁻³⁴J*s
e = 6.626x10⁻³⁴J*s*3.43x10¹⁴s⁻¹
e = 2.27x10⁻¹⁹JA compound containing only carbon, hydrogen, and oxygen is analyzed using combustion analysis. When 50.1 g of the compound is burned, 91.8 g of carbon dioxide and 25.1 g of water are collected. In order to determine the moles of carbon in the compound, first determine the moles of carbon dioxide that were produced from the combustion.
Answer:
[tex]C_{3}H_4O_2[/tex]
Explanation:
Hello,
In this case, since the carbon of the initial compound is present in the carbon dioxide product, we can compute the mass and moles of carbon in the compound:
[tex]n_C=91.8g CO_2*\frac{1molCO_2}{44gCO_2} *\frac{1molC}{1molCO_2} =2.09molC\\\\m_C=91.8g CO_2*\frac{1molCO_2}{44gCO_2} *\frac{1molC}{1molCO_2}*\frac{12gC}{1molC} =25.0gC[/tex]
Next, the mass and moles of hydrogen in the compound, is contained in the yielded amount of water, thus, we compute the mass and moles of hydrogen in the compound:
[tex]n_H=25.1gH_2O*\frac{1molH_2O}{18gH_2O} *\frac{2molH}{1molH_2O} =2.79molH\\\\m_H=25.1gH_2O*\frac{1molH_2O}{18gH_2O} *\frac{2molH}{1molH_2O} *\frac{1gH}{1molH} =2.79gH[/tex]
In such a way, the mass of oxygen comes from the mass of the compound minus the mass of carbon and oxygen:
[tex]m_O=50.1g-25.0g-2.79g=22.31gO[/tex]
And the moles:
[tex]n_O=22.31gO*\frac{1molO}{16gO}=1.39molO[/tex]
Then, we compute the subscripts by diving the moles of C, H and O by the moles of oxygen as the smallest moles:
[tex]C:\frac{2.09}{1.39}=1.5 \\\\H:\frac{2.79}{1.39}=2\\ \\O:\frac{1.39}{1.39} =1[/tex]
After that, we write:
[tex]C_{1.5}H_2O[/tex]
Which must be shown in whole number only, thereby we multiply the subscripts by 2, so the empirical formula turns out:
[tex]C_{3}H_4O_2[/tex]
Best regards.
2NH.
N2 + 3H2
Reactants
Product
On the balanced equation above, how many
atoms of each element are in the reactant?
N =
H =
Answer:
N=2
H=6
Explanation:
1.Balance a chemical equation in terms of moles.
2.Use the balanced equation to construct conversion factors in terms of moles.
3.Calculate moles of one substance from moles of another substance using a balanced chemical equation.
The law of conservation of matter says that matter cannot be created or destroyed. In chemical equations, the number of atoms of each element in the reactants must be the same as the number of atoms of each element in the products.
(P.s it could also be where you have to solve it in which you have to simplify it first then solve it.) like adding them all up.
Hope this is the answer. :)
What is the atomic number of arsenic (As)?
O A. 33
O B. 15
C. 75
D. 4
SUB
Answer:
33
Explanation:
Given the mass of carbon on the periodic table (12.01 amu), which isotope do you think is the most abundant? Explain WHY in complete sentences. *
Answer:
Carbon-12
Explanation:
Carbon-12 is a carbon with 6 protons and 6 neutrons. Since the AMU for an element is calculated by averaging all naturally occurring isotopes, we can see that 12 in the most abundant. (Since 12.01 is very close to 12, the only reason it is not exactly 12 is because there are other isotopes like carbon-13 or carbon-14 but in low amounts)
What is the mass in grams of 5.9 mol c8 h18
Answer:
mass = density × volume = 0.67 × 1.00 = 0.67 kg = 670 g. The molar mass of octane, C8H18, is 8 × 12.01 (C) + 18 × 1.008 (H) = 114.224.
Explanation:
Element X
Is a Solid at room temperature
Is a metalloid and semiconductor of heat and
electricity
Reacts with Oxygen to form XO2,
compounds and with chlorine to form XCI4,
compounds
Has an average atomic mass that is 2.34
times greater than the standard for atomic
mass(Carbon-12)
Examples 36
A cylinder is 350cm³ long and two gases A and B have relative molecular weights of 64 and 16 respectively. If the two gases, at the same temperature and pressure, are released simultaneously at both ends determine the distance from one end at which the gases meet.
2x = 350- x
3x = 350
x = 350/x
therefore,
x = 116.67cm.
so, (350 - x)cm³ = (350- 166.67)cm³ = 233.33cm³
Hence distance covered by gas A is 116.67cm that by B is 233.33cm
You are given 3 liquid samples – A, B, C and told that one is water, one is ethanol, and one is ether (d=0.700 g/mL). Each sample is 10.0 mL. the masses are as follows: A = 10.0 g, B= 7.00 g, C = 8.00 g. Identify each of the substances using density problems.
Answer:
im just trying to get work done i will help u if i knew it
What is the volume of 4.62 g of mercury? The density of mercury is 13.5 g/cm3.
Answer:
The answer is 0.342 cm³Explanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 4.62 g
density = 13.5 g/cm³
We have
[tex]volume = \frac{4.62}{13.5} \\ = 0.3422222...[/tex]
We have the final answer as
0.342 cm³Hope this helps you
Please help me!!!:)))
Answer:
blocks 1 and 2 the rhdh huff hgfhh5
What is the mass in grams of 2.4 x 10-2 mol K2SO4
the coefficient of 02 is needed to balance the equation C3h8+O2+3co2+4H20
Answer:The anwser is 5
Explanation:
give reason deliquescent substance truns into liquid when exposed to atmosphere air
What can you infer about the likely occurrence of the other isotopes in each of the
above elements? Explain your reasoning.
Answer:
Most common has the same or closest mass because it is closer to the original’s mass.
Explanation:
I got it from the answer key
Read more here:
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How many moles would be in 24.23 grams of SrSO4?
Use two digits past the decimal for all values.
Answer:
about 0.13 mol
Explanation:
To find number of mols when given grams you first have to find the molar mass of the compound. This is done by adding up the atomic masses of the element in the compound. So Sr= 88 g/mol S=32 g/mol and O=16 g/mol. Then 88+32+(16x4)=184. Then using this you can convert from grams to mols by dividing the grams by the molar mass. So, 24.23/184 equals about 0.13 mol.
Define a function compute_gas_volume that returns the volume of a gas given parameters pressure, temperature, and moles. Use the gas equation PV
Answer:
def compute_volume(pressure,moles,temperature):
volume = (8.314 * moles * temperature)/pressure
print("Volume: "+str(volume))
Explanation:
This line defines the function
def compute_volume(pressure,moles,temperature):
This line calculates the volume
volume = (8.314 * moles * temperature)/pressure
This line prints the calculated volume
print("Volume: "+str(volume))
Balance the equations by inserting coefficients as needed.
equation 1:
CaCO3 + HCl -> CaCl2 + CO2 + H2O
CaCO3+HCl⟶CaCl2+CO2+H2O
equation 2:
C6H12O2 + O2 -> CO2 + H2O
C6H12O2+O2⟶CO2+H2O
Answer:
1. CaCO3 + 2HCl → CaCl2 + H2O + CO2
2. C6H12O2 + 8O2 → 6CO2 + 6H2O
Explanation:
The balanced chemical equation is (i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
What is balanced chemical equation?An equation with equal amounts of every atom of an element on both endpoints of the arrow was called a balanced equation.
Given chemical equation is:
(i) CaCO3+HCl⟶CaCl2+CO2+H2O
It can be seen that in left side of the chemical equation count of chlorine atom is one while right side of the chemical equation it is two. So, by multiplying 2 as a coefficient in the right side of the equation. Balanced chemical equation will be
CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+O2⟶CO2+H2O
It can be seen that, there are 12 hydrogen in the left side of the reaction while it is two hydrogen in the right side of the reaction. By multiplying 6 as a coefficient of hydrogen. Hence, the balanced chemical equation will be
C6H12O2+ 8O2⟶CO2+6H2O
The balanced chemical equation is
(i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
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The same ball is hit again and experiences a net force of 3.5 N instead. What is the acceleration of the volleyball?
Answer:
I hope this helped :)
Explanation:
a=f/m
a=3.5N/.25 kg
a=14m/s2
The acceleration of the volleyball is 14 m/s²
A force is defined to be a pull or a push acting on an object. The force exerted on an object can be said to be determined if the mass of the object is known.
It can be calculated by using the expression;
Force (F) = mass (m) × acceleration (a)
From the given information;
The net force acting on the ball after it hits again = 3.5 NLet assume that the mass of the ball is 0.25 kg since it is not given∴
The acceleration of the above expression can be computed as:
acceleration (a) = Force (F) / mass (a)
acceleration (a) = 3.5 / 0.25
acceleration (a) = 14 m/s²
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Consider the balanced equation below. Upper P Upper C l Subscript 3 Baseline + Upper C l Subscript 2 Baseline right arrow Upper P Upper C l Subscript 5. What is the mole ratio of PCl3 to PCl5? 1:1 2:1 3:5 5:3
Answer : The mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Explanation :
Balanced chemical reaction : It is a chemical reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
The balanced chemical reaction is:
[tex]PCl_3+Cl_2\rightarrow PCl_5[/tex]
By the stoichiometry of the reaction we can say that 1 mole of [tex]PCl_3[/tex] reacts with 1 mole of [tex]Cl_2[/tex] to give 1 mole of [tex]PCl_5[/tex].
From this we conclude that the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Hence, the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Answer:
A
Explanation:
If the density of aluminum is 2.7g/ml, what is the volume of 12.0g?
Answer:
The answer is 4.44 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{12}{2.7} \\ = 4.4444444....[/tex]
We have the final answer as
4.44 mLHope this helps you
80.20%, 11.01 amu
19.80%, 10.81 amu
What is the Average Atomic Mass?
g Calculate the mass percent of sodium bicarbonate in the solution that has 7.00 g of solution and 0.052 Kg of water.
Answer:
11.86%
Explanation:
First, we convert both solvent and solute to the same unit, say, kg. We have.
Mass of Sodium Bicarbonate = 7g = 7/1000 kg = 0.007 kg
Mass of water = 0.052 kg.
Formula for the mass percent is
% of sodium bicarbonate = [(mass of sodium bicarbonate) / (mass of total solution) * 100%]
Total mass of solution = 0.007 + 0.052 Total mass of solution = 0.059
% of sodium bicarbonate = 0.007 / 0.059 * 100%
% of sodium bicarbonate = 11.86%
Therefore, the mass percent of sodium bicarbonate I'm the solution is 11.86%