Answer:
1 × 10⁸ He atoms
Explanation:
Step 1: Given data
Diameter of a helium atom (d): 1 × 10² pmTotal distance to be covered (D): 1 cmStep 2: Convert "d" to meters
We will use the conversion factor 1 m = 10¹² pm.
1 × 10² pm × (1 m / 10¹² pm) = 1 × 10⁻¹⁰ m
Step 3: Convert "D" to meters
We will use the conversion factor 1 m = 100 cm.
1 cm × (1 m / 100 cm) = 0.01 m
Step 4: Calculate the number of atoms of He required
We will use the following expression.
D/d = 0.01 m / 1 × 10⁻¹⁰ m = 1 × 10⁸
Octet Rule states that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. Depending on this fact answer the following question :
1)What is an incomplete octet?
2)What is an odd-electron molecule?
3)Why are there extra electrons in the expanded octet?
Answer:
1. an incomplete octet is an valence shell that is not fully stable since it doesn't have 8 electrons
2.an odd electron molecule is a molecule that has an odd number of electrons but is still stable
3. there are extra electrons in an expanded octet because the molecules' central atoms make extra bonds that don't comply with the octet rule.
Explanation:
QUESTION TWO
(a) Derive Nernst equation for measuring the EMF of the cell
(b) Calculate the emf of the cell
[3]
Zn Zn? (0.001M)|| Agt (0.1M)| Ag
The standard potential of Ag/Ag half-cell is +0.80 V and Zn/Zn. is -0.76 V
(c) Name different types of standard electrodes used for the determination of pH
of a solution by EMF measurement Discuss the working of Glass Electrode
for the determination of pH of a solution
(d) 0.1978 g of copper is deposited by a current of 0.2 ampere in 50 minutes.
What is the electrochemical equivalent of copper?
[3]
Answer:
Screenshot
Explanation:
What volume, in mL, of concentrated 16 M nitric acid would you need to use in order to prepare 500.0 mL of a 0.250 M HNO3(aq) solution?
Given :
Initial concentration of nitric acid, [tex]C_1 = 16\ M[/tex].
Final concentration of nitric acid, [tex]C_2 = 0.250 \ M[/tex].
Volume of [tex]HNO_3[/tex], [tex]V _2= 500\ mL = 0.5\ L .[/tex]
To Find :
Volume needed( [tex]V_1[/tex] ).
Solution :
We know,
[tex]C_1V_1 =C_2V_2\\\\16 \times V_1 = 0.250 \times 0.5 \\\\V_1 = \dfrac{0.250 \times 0.5}{16}\\\\V_1 = 0.0078125\ L = 7.8125 \ mL[/tex]
Hence, this is the required solution.
The diagram represents a plant leaf cell and two different molecules used in the process of photosynthesis. Molecule 1 and 2 are most likely
A. Carbon dioxide and water
B. Nitrogen and water
C. carbon dioxide and nitrogen
D. Nitrogen and oxygen
PLEASE HELP. ONLY IF YOU KNOW THE ANSWER
Answer:
24. B
25. B
26. B
Explanation:
24. As depicted in the image attached, all living organisms including animals undergo cellular respiration, which is the process whereby sugar molecule is broken down to release energy (ATP). In this process, CARBON DIOXIDE (CO2) is released as a product. The equation is as follows:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
On the other hand, plants undergo a unique process called photosynthesis in order to synthesize their food (sugars) and hereby release oxygen gas in the process. Based on the diagram in option B, plants release oxygen using CO2, while animals release CO2 using O2.
25. The structure depicted in the image of this question is an organelle called MITOCHONDRIA. The mitochondrion is the site of cellular respiration (Krebs cycle and ETC) in eukaryotic cells.
26. Photosynthesis is a metabolic process unique to the cells of autotrophic organisms like green plants. It is the process where they synthesize their food in form of organic molecules using SUNLIGHT as a source of energy.
6CO2 + 6H2O + sunlight → C6H12O6 + 6O2
Draw a simple transverse wave and label the wavelength.draw it on a piece of paper
Answer:
I need this too but nobody knows how :(
Explanation:
Which is a property of potassium (K)? O A. It is dull and brittle. O B. It is not reactive. O C. It is white and hard. D. It is extremely reactive.
Answer:
D. It is extremely reactive.
Explanation:
Hello!
In this case, since potassium is an alkali metal, it is known those are extremely reactive because the energy required to ionize them is very low, it means they react so easily. For instance, even in the presence of water, potassium is able to react and form a purple flame as a product of the reaction:
[tex]2K+2H_2O\rightarrow 2KOH+H_2[/tex]
As well as potassium, the rest of the elements belonging to the alkali metals series are extremely reactive; therefore the answer is D. It is extremely reactive.
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Drag each number to the correct location on the equation. Each number can be used more than once, but not all numbers will be used.
Balance the equation with the correct coefficients.
2
3
4
5
KClO3→ KCl+. O2
Answer:
2KClO₃ → 2KCl + 3O₂
Explanation:
The unbalanced expression is given as:
KClO₃ → KCl + O₂
The reaction equation above is unbalanced and we need to choose between the numbers 2,3,4 and 5 to finally the correct expression that will obey the law of conservation of mass.
aKClO₃ → bKCl + cO₂
Let a, b and c be the numbers that will balance the expression;
Conserving K;
a = b
Conserving Cl;
a = b
Conserving O;
3a = 2c
let a = 1, b = 1 and c = [tex]\frac{3}{2}[/tex] multiply through by 2;
a = 2, b = 2 and c = 3
So, the balance expression insert;
2KClO₃ → 2KCl + 3O₂
If a gas at 315 k has a volume of 1.50 l , what is the volume of the gas when the temperature is reduced to 215 k
Answer:
1.02 L.
Explanation:
For this problem, you have to apply one of the gas laws --Charles' Law. It is as follows: V1/T1 = V2/T2. Substituting the values in and using sig figs, we get 1.02 L.
Answer:
1.02
Explanation:
A group of organs working together to perfrom a certain function called
Answer:
group. hfdzybidddiklllnjjooolll
Answer:
An organ system
Explanation:
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You have 165.5 g of Ba(OH)2.
How many moles of barium ions are present in part 1?
_____ mol Ba2+
How many moles of hydroxide ions are present in Part 1?
_____ mol OH1-
Answer:
moles of Ba²⁺ : 0.97 mol
Moles of OH⁻ : 1.94 mol
Explanation:
Given data:
Mass of Ba(OH)₂ = 165.5 g
Moles of barium ions = ?
Moles of hydroxide ion = ?
Solution:
Number of moles of barium hydroxide:
Number of moles = mass/molar mass
Number of moles = 165.5 g/ 171.34 g/mol
Number of moles = 0.97 mol
one mole of barium hydroxide contain one mole of Ba²⁺ and 2 mole of OH⁻ ion.
Thus in 0.97 moles of barium hydroxide,
moles of Ba²⁺ :
0.97 mol × 1 = 0.97 mol
Moles of OH⁻ :
0.97 mol × 2= 1.94 mol
These traits describe either a chemical or a nuclear reaction. Which statements describe a nuclear
reaction? Check all that apply.
involves the loss, gain, or sharing of electrons
may involve a change in total mass
involve relatively low energy changes
occur outside the nucleus
involve very high-energy changes
o involve changes in nuclides when decay occurs
Answer:
may involve a change in total mass
involve very high-energy changes
involve changes in nuclides when decay occurs
Explanation:
A nuclear reaction is different from a typical chemical reaction. The reaction occurs within the nucleus and involved nuclear materials.
Most nuclear reactions involves a change in mass due to the attenuation of the nuclear materials. Mass is converted to energy in nuclear reactions. Nuclear reactions are usually very high energy processes and they release a significant amount of energy. The nuclide changes as new atoms are formed by the process.Need help on chemistry
Answer:
B
Explanation:
Protons are located in the nucleus, which takes out c
Electrons are in specific shells, so b is the answer
an atom of x is twice heavier as one carbon 12 atom . calculate relative atomic mass of elements x
Answer:
12*2= 24
Mg 24 is twice heavier than carbon
Explanation:
The atomic mass of one carbon 12 atom = 12 g/mol
Relative atomic mass [tex](A_{r})[/tex] of an element is the mass of one of its atoms relative to 1/12 the mass of one atom of carbon-12.
Relative atomic mass [tex](A_{r})[/tex] is given by the formula
[tex](A_{r})[/tex] = (Average mass of an atom ×12)/(mass of one atom of carbon-12)
From the question, x is twice heavier as one carbon 12 atom
∴ mass of x = 2 × 12 g/mol
mass of x = 24 g/mol
Then, the relative atomic mass of elements x is calculated thus
[tex]A_{r}= \frac{24gmol^{-1} \times 12}{12 gmol^{-1} }[/tex]
[tex]A_{r} = 24 \\[/tex]
Hence, the relative atomic mass of elements x is 24.
(NOTE: Relative atomic mass is unitless)
Learn more on relative atomic mass here: https://brainly.com/question/16824270
⦁ How many moles of carbon dioxide will be produced by the complete reaction of 2.0 mol of glucose (C6H12O6), according to the following equation?
C6H12O6 + 6O2 → 6CO2 + 6H2O
Answer:
i think 12 moles of CO2 will be produced
why we add PH10 When we determine the zn ion
Answer:
to make it basic from acidic
I need help and fast plzzzzzzzzz
Answer:
A is condensation
B is Conduction
C is erosion
D is radiation
E is deposition
Explanation:
Look at picture and answer will mark brainliest.
Answer:
A
Explanation:
1) Which of the following statements are correct? Rewrite each false statement to make it true.
a) Elements listed in rows on the periodic table are in the same family.
b) Elements in the same column of the periodic table exhibit the same physical properties
c) Elements in the same group are in the same family.
d) Elements that are side by side on the periodic table belong to the same period.
21 Mamath
Answer:
a) Elements listed in rows on the periodic table are in the same family - false
Explanation:
Elements listed in groups /columns on the periodic table are in the same family.
The false statement is:
a) Elements listed in rows on the periodic table are in the same family.
Elements in the periodic table:In a periodic table, the elements are arranged in increasing order of atomic number. There are 7 periods and 18 groups in a periodic table.
The statement which is false is:
a) Elements listed in rows on the periodic table are in the same family.
The correct statement will be:
a) Elements listed in rows on the periodic table belongs to a different family.
These elements will have different properties and thus placed in periodic table.
Find more information about periodic table here:
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Reactivity occurs when a substance reacts with another substance, changing it into a ____?
Answer:b
Explanation:
An unknown compound has the following chemical formula: where stands for a whole number. Measurements also show that a certain sample of the unknown compound contains of nitrogen and of oxygen. Write the complete chemical formula for the unknown compound.
The question is incomplete, the complete question is;
An unknown compound has the following chemical formula:
N2Ox
where x stands for a whole number.
Measurements also show that a certain sample of the unknown compound contains 3.7 mol of oxygen and 2.45 mol of nitrogen.
Write the complete chemical formula for the unknown compound.
Answer:
The complete formula of the compound is N2O3.
Explanation:
Given;
Number of moles of N = 2.45 moles
Number of moles of O = 3.7 moles
Chemical formula of unknown compound = N2Ox
From the ratio of the number of moles of N to O;
2/x = 2.45/3.7
2 * 3.7 = x * 2.45
x = 2 * 3.7/ 2.45
x =3
Hence the complete formula of the compound is N2O3.
A cylinder of argon gas contains 50.0 L or Ar at 18.4 atm and 'C. How many moles of argon are in the cylinder?
A cylinder of argon gas contains 50.0 L of Ar at 18.4 atm and 127 °C. How many moles of argon are in the cylinder?
Number moles of Argon : 28.03
Further explanationGiven
The volume of gas=50 L
P = 18.4 atm
T = 127+273=400 K
Required
moles of Argon
Solution
Use ideal gas Law :
[tex]\tt n=\dfrac{PV}{RT}\\\\n=\dfrac{18.4\times 50}{0.08205\times 400}\\\\n=28.03[/tex]
Which statement is correct concerning hereditary information?
A. A chromosome is composed of many genes.
B. A gene is composed of many chromosomes.
C. Each chromosome carries the same information.
D. Each gene carries the same information.
Answer:
the answer to this question is option A mark me as brainliest
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what deos sedimentation mean
Answer:
This is the tendency for particles in suspension to settle out of fluid in which they are contained and come to rest against a barrier.
Explanation:
In sedimentation, the particles are in a fluid and under the influence of forces , for example, gravitational forces, they settle and then come to rest when faced with a barrier.
The settling process is the process in which the particles fall out of liquid and sedimentation is the end of the process.
How much HCl exists in 347 mL of 0.48 M
solution of HCI?
Answer in units of mol.
Answer:
Number of moles of HCl = 0.17 mol
Explanation:
Given data:
Volume of solution = 347 mL
Molarity of solution = 0.48 M
Number of moles of HCl present = ?
Solution:
Formula:
Molarity = number of moles of HCl / volume in L
Volume in L:
347 mL× 1L / 1000 mL
0.347 L
by putting values in formula:
0.48 mol/L = number of moles / 0.347 L
Number of moles = 0.48 mol/L × 0.347 L
Number of moles = 0.17 mol
28. Describe the molecular geometry and hybridization of the N, P, or S atoms in each of the following compounds. (a) H3PO4, phosphoric acid, used in cola soft drinks (b) NH4NO3, ammonium nitrate, a fertilizer and explosive (c) S2Cl2, disulfur dichloride, used in vulcanizing rubber (d) K4[O3POPO3], potassium pyrophosphate, an ingredient in some toothpastes
Answer:
See explanation
Explanation:
The molecular geometry of an atom is connected to the number of electron pairs that surround it(whether lone pairs or bonding pairs) as well as its hybridization state. We shall now examine the N, P, or S atoms in each of the following compounds.
a)
In H3PO4, P has a tetrahedral molecular geometry and is sp3 hybridized.
b) In NH4NO3
N is sp3 hybridized in NH4^+ and sp2 hybridized in NO3^-. Also, N is tetrahedral in NH4^+ but trigonal planar in NO3^-.
c) In S2Cl2, we expect a tetrahedral geometry but as a result of the presence of two lone pairs on each sulphur atom, the molecular geometry is bent. The sulphur is sp3 hybridized.
d) In K4[O3POPO3], each phosphorus atom is in a tetrahedral molecular geometry and is sp3 hybridized.
What is a Newton?
explain please
Answer:
it is the unit of Force
Explanation:
force is equal to Newton
What is electronegativity
Answer:
Electronegativity, symbol χ, measures the tendency of an atom to attract a shared pair of electrons (or electron density). An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons.
Cl2 + H2 + 2HCI
In the reaction above, the coefficient of Cl2 is
blank The subscript of Cl2 is blank
Answer:
1 and 2
Explanation:
The given equation is:
Cl₂ + H₂ → 2HCl
A coefficient is the variable or number before a chemical specie.
In this reaction Cl₂ and H₂ are the reactants;
The coefficient of Cl₂ is 1,
H₂ is 1,
HCl is 2
The subscript is the number to the lower power after a chemical specie is denoted.
For Cl₂, it is 2
A number before a chemical atom or molecule is called a coefficient. The coefficient of chlorine is one (1), and its subscript is two (2).
What subscript?A subscript is a number or symbol written at the bottom right of the chemical atom or the molecule in a compound.
The balanced chemical reaction is shown as:
[tex]\rm Cl_{2} + H_{2} \rightarrow 2HCl[/tex]
The coefficient in chlorine is 1, hydrogen is 1, and hydrochloric acid is 2. The subscript in chlorine gas is 2, and hydrogen gas is 2.
Therefore, the coefficient is 1, and the subscript is 2.
Learn more about coefficient here:
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True or fase all fossils come from dinosaurs?
Answer:
Hella false
Explanation:
big cap.
hope this helped, please make me brainliest