Answer:
The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.
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how is electrovalent bond formed ? Describe with an example .
Answer:
For example, the bond between the sodium and chlorine atoms in sodium chloride (NaCl) is formed by the transfer of an electron from sodium to chlorine, creating Na + and Cl – ions. ... The electrostatic attraction between these ions provides the bonding in NaCl.
which statement is generally true about CaCaI2 ?
Explanation:
"Its bonds are formed by large differences in electronegativity" is the statement among the choices given in the question that is generally true about CaCl2.
Which of the following is true about science?
It is not influenced by social conditions.
Economic concerns may prevent it from solving problems.
It is not determined by external local factors.
Political conditions are unable to influence it.
Answer:
The correct answer is - Economic concerns may prevent it from solving problems.
Explanation:
Scientific research is influenced by various factors. Science helps in the solving of human problems. However, scientific research can need to be supported by many factors such as Huge amounts of money that need to be invested in performing out particular scientific research to solve problems.
For science, there are requirements of Laboratories and lab supplies such as the equipment and experts need to train the personnel on how to use it.
Thus, economic factors play a huge role in scientific research.
If an atom of chlorine (CI) were to ionize, it would
electron(s).
Answer:
Explanation:
As per being a Group 7 element, it would gain one electron, which changes it's charge to 1-. It is therefore negatively charged, having a full outer shell of 8, having its electronic structure to be at 2,8,8.
What is the density of ammonia (NH3) at 273 K and 1.00 atm?
A - 0.7601 g/L
B - 0.982 g/L
C - 1.23 g/L
D - 2.43 g/L
Answer:
0.7602 g/L
Explanation:
We'll begin by calculating the molar mass of NH₃. This can be obtained as follow:
Molar mass of NH₃ = 14.01 + (3×1.01)
= 14.01 + 3.03
= 17.04 g/mol
Finally, we shall determine the density of ammonia, NH₃. This can be obtained as follow:
Temperature (T) = 273 K
Pressure (P) = 1 atm
Molar mass of NH₃ (M) = 17.04 g/mol
Gas constant (R) = 0.0821 atm.L/Kmol
Density (D) =?
D = PM / RT
D = (1 × 17.04) / (0.0821 × 273)
D = 17.04 / 22.4133
D = 0.7602 g/L
Answer:
It is A
Explanation:
Plz help I will give brainliest
Answer:
1. Fr
2. cl
3.H20
4.2 mole
5. 3
6. c
05) Identify the statement that is true about atoms as they pass through the rock cycle. a. Those that were adjacent to each other remain near each other. b. They do not move through the rock cycle at the same rate. c. They move through the rock cycle in the same manner. d. They stay within the same mineral.
Answer:
b. They do not move through the rock cycle at the same rate
Explanation:
The rock cycle is the phenomenon used to describe the interrelation of the three forms in which rocks exists, and a rock is changed between forms due to the Earth's geologic process, such as erosion, weathering and plate tectonics
The rock cycle involves both chemical and physical transformation of rocks and therefore, the atoms and compounds make and cut connections, such that the rate at which each atom move through the rock cycle at different rate
what is bonding in chemistry
Explanation:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.
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Answer:
Check Down
Explanation:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bond.
Products formed when chlorine is produced by the electrolysis of concentrated sodium chloride solution
The products formed during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.
ELECTROLYSIS is the process by which electrolytes allows electric current to pass through it and is decomposed on the process.
CHLORINE is an element which can be produced industrially through the process of electrolysis of brine (concentrated sodium chloride solution). When sodium chloride is dissolved in water, it's ions separate and are capable of conducting electricity.
The products formed during this process includes:
chlorine sodium hydroxide and hydrogen gas.CHLORINE: this is released at the positive electrode during electrolysis. It is used for the following purposes:
it is used for sterilisation of water for domestic and industrial use it is used as a bleaching agent for cotton, linen and wood-pulp.SODIUM HYDROXIDE: this remains in the solution during electrolysis. It is used for the following:
processing food products, removing pollutants from water and manufacture of paper.HYDROGEN GAS:this is released at the negative electrode during electrolysis. this is used for the following:
manufacture of ammonia, hydrochloric acid and methanol it serves as constituents of many gaseous fuels such as water gas and coal gasTherefore other products during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.
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https://brainly.com/question/13123512
WM "Please write the molecular formula for the following by criss cross method. 1. Calcium nitrate 2. Sodium bicarbonate 3. Magnesium nitrite 4. Sodium chloride 5. Hydrogen sulphate 6. Hydrogen chloride T-Aluminium bisulphate 8 Aluminium chloride 9. Aluminium sulphate 10. Hydrogen Nitrate
Answer:
1 Ca(NO3)2
Calcium- Ca, Valency 2
Nitrate- NO3, Valency 1
AFTER CRISS CROSS:
Ca1(NO3)2
Ca(NO3)2
2 sodium bicarbonate = NaHCO3
Na = Sodium = (Na)+
HCO3 = bicarbonate = (HCO3) -
Na HCO3
3 magnesium nitrite
+2 _ 1
Mg2(NO3)2
4 Na Cl
+1 _1
formula NaCl
5 hydrogen sulphide
H SO4
+1 _2
formula H2SO4
6 H Cl
+1 _1
HCl
7 AL2 HSO4
+2 -2
AL2(HSO4)3
8 NH4 Cl
+1 _1
NH4Cl
9 NH4 SO4
+1 _2
(NH3)2SO4
10 H NO3
+1 _1
HNO3
accessory pigments A) transfer electrons to reaction center chlorophylls. B) transfer energy to reaction center chlorophylls. C) transfer electrons from reaction center chlorophylls to pheophytins. D) transfer electrons from reaction center chlorophylls to ferredoxin. E) All of these statements are true.
Answer:
B. Transfer energy to reaction center chlorophylls.
Explanation:
Accessory pigments absorbs sunlight, these compounds are found in photosynthetic organisms, which work in conjunction with chlorophyll. Acessory pigments absorbs and transfer light energy to reaction center chlorophylls.
Which atom is abundant in the universe
Answer:
hydrogen is abundant in nature
Write down the constituent elements present in the following compounds.
a. Sodium Sulphate
b. Baking Soda
c. Limestone
d. Bleaching powder
e. Ammonia
f. Caustic Soda
g. Glucose
h. Ammonium Carbonate
I. Acetic acid
j. sulphuric acid
Answer:
in sodium sulphate there is sodium an sulphur
When 38^88Sr decays to 34^84Kr, a(n) ______________ is emitted
Answer:
The correct answer is - alpha particle and positron.
Explanation:
In this question, it is given that, 38^88Sr decays to 34^84Kr, which means there is an atomic number decrease by 4, 38 to 34, and atomic mass decreases by 4 as well 88 to 84.
A decrease in the atomic mass is possible only when there is an emission of the alpha particle as an alpha particle is made of 2 protons and 2 neutrons. If an atom emits an alpha particle, there is a change in atomic number as it decreases by two, and its mass number decreases by four.
So after the emission of an alpha particle, the new atom would be
38^88Sr=> 36^84X => 34^84Kr
so there is also two positron emission that leads to decrease in atomic number by one with each emission:
38^88Sr=> 2^4He+ 36^84X => 36^84X + 2(1^0β+) => 34^84Kr
Positron decay is the conversion of a proton into a neutron with the emission of a positron that causes the atomic number is decreased by one, which causes a change in the elemental identity of the daughter isotope.
If 56 grams of carbon monoxide burns in oxygen to produce 88 grams of carbon dioxide, the mass of oxygen involved in the reaction is
grams.
The answer is 32 grams!
hope I helped
H3C6H507 + H2O + H3O+ + H2C6H507
acid
base
Explanation:
an acid will give away a proton and become a conjugate base.
A base will accept a proton and become a conjugate acid.
the solubility of sugar is 250 at 60° what does it mean.
please helpp anyone please help...
Answer:
sry i don't know answer of This question
as the balloon rises what happens to the external pressure
Answer:
As the ballon rises higher the atmospheric pressure will drop if the ballon is made of an elastic material,it will stretch to allow the gas inside it to expand
how can you separate mixture of suphur, nacl and nh4cl
Answer:
Ammonium chloride, iron ,Sulphur and salt mixed together... they can be separated in the following methods.
1. Ammonium chloride is separated by sublimination... NC4CI is sublimable. Heat the mixture in a china dish and collect the funds of NC4CI (sublimable substance)
2. Bring a magnet close to the remaining mixture. Iron is magnetic substance and thus, it will be attracted towards the magnet. Iron is separated.
3. Sulphur is insoluble in water and salt is soluble. Add water to the remaining mixture and then wait for sedimentation. Separate the sulphur by decantation.
4. Heat the filtered salt solution to obtain salt.
Which of the following is an example of a molecule?
A. A sodium atom forms a metallic bond with another sodium atom.
B. A hydrogen atom forms a covalent bond with a chlorine atom.
C. A sodium atom forms an ionic bond with a chlorine atom.
D. A sodium atom forms a metallic bond with another sodium atom.
Answer:
The answer is B. A hydrogen atom forms a convalent bond.........
How many Calcium (CA) Atoms are in Calcium Oxide
Prepare a project report on various samples of a) a mixture b) a compound c) an element (metal or nonmetal)
Answer:
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
Example: Water decomposes into a mixture of hydrogen and oxygen when an electric current is passed through the liquid. Hydrogen and oxygen, on the other hand, cannot be decomposed into simpler substances. They are therefore the elementary, or simplest, chemical substances - elements.
Each element is represented by a unique symbol. The notation for each element can be found on the periodic table of elements.
The elements can be divided into three categories that have characteristic properties: metals, nonmetals, and semimetals. Most elements are metals, which are found on the left and toward the bottom of the periodic table. A handful of nonmetals are clustered in the upper right corner of the periodic table. The semimetals can be found along the dividing line between the metals and the nonmetals.
Explanation:
100cm³ of ethane gas diffuses through a porous plug in 100 seconds.What is the molecular mass of the gas Q if 100cm³ of the gas diffuses through the same plug in 121 secknds under the same condition?(C=12.0,H=1.0)
Answer:
The molar mass of gas Q is 43.923 g/mol
Explanation:
The given volume of ethane gas that diffuses through a porous plug in 100 seconds = 100 cm³
Therefore;
The rate of diffusion of ethane gas through the porous plug, [tex]v_{ethane}[/tex], is given as follows;
[tex]v_{ethane}[/tex] = (100 cm³/100 s) = 1 cm³/s
The molar mass of ethane, C₂H₆ = 2×12 g/mol + 6×1 g/mol = 30 g/mol
The given volume of gas, Q, that diffuses through a porous plug in 121 seconds = 100 cm³
∴ The rate of diffusion of the gas, Q, [tex]v_Q[/tex] = 100/121 cm³/s
Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of the molecular mass of the gas
Mathematically, we have;
[tex]\dfrac{v_A}{v_B} =\sqrt{\dfrac{m_B}{m_A} }[/tex]
Where;
[tex]v_A[/tex] = The rate of diffusion of gas A
[tex]v_B[/tex] = The rate of diffusion of gas B
[tex]m_A[/tex] = The molar mass of the gas A
[tex]m_B[/tex] = The molar mass of the gas B
Therefore, for ethane and gas Q, measured under the same condition, we have;
[tex]\dfrac{v_{ethane}}{v_Q} =\sqrt{\dfrac{m_Q}{m_{ethane}} }[/tex]
[tex]\dfrac{1 \ cm^3/s}{\dfrac{100}{121} \ cm^3/s} =\sqrt{\dfrac{m_Q}{30 \ g/mol} }[/tex]
[tex]m_Q = \left ({\dfrac{121}{100} } \right) ^2 \times 30 \ g/mol = 43.923 \ g/mol[/tex]
The molar mass of gas Q, [tex]m_Q[/tex] = 43.923 g/mol.
Predict the approximate Ksp of Cuz(AsO4)2 based on the measured potential of Cell 7. Use the equation given in the Background.
a. 1 x 10^-35
b. 4 x 10^14
c. 5 x 10^-17
d. 2 x 10^-21
Answer:
a. 1 x 10^-35
Explanation:
The correct compound given is: [tex]\mathsf{Cu_3(AsO_4)}_2[/tex]
To predict the approximate Ksp value of the given compound, we will need to express the oxidation-reduction half-reaction of the compound and its dissociation, then, we will use the Nernst equation to determine the approximate Ksp value.
To start with the reduction half-reaction:
[tex]\mathsf{Cu_3(AsO_4)_{2}(s) + 6e^- \to 2As O_{4}^{3-}_{(aq)}+3Cu(s) }[/tex]
The oxidation half-reaction is:
[tex]\mathsf{3Cu(s) \to 3CU^{2+}_{(aq)} + 6e^-}[/tex]
The overall cell reaction now is:
[tex]\mathsf{Cu_3(AsO_4)_{2}(s) \to 3Cu^+ (aq) + 2As O_{4}^{3-}_{(aq)} }[/tex]
From the reduction half-reduction, the number of moles of electrons (n) transferred is 6 moles.
By applying the Nernst equation:
[tex]\mathsf{E_{cell} = E^0_{cell} -\dfrac{0.0591V}{n}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]
At standard conditions;
The standard cell potential [tex]\mathsf{E^0_{cell} = -0.342 \ V}[/tex]
and [tex]\mathsf{E_{cell} = 0 \ V}[/tex] since it is at equilibrium.
∴
[tex]\mathsf{0 = -0.342 -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 } \\ \\ \\ \mathsf{0.342 = -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = \dfrac{-(0.342)*6}{0.0591 }}[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = -34.7}[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 \simeq -35}[/tex]
[tex]\mathsf{[Cu^{2+}]^3[AsO_4^{3-}]^2 = 10^{-35}}[/tex]
[tex]\mathbf{K_{sp} = [Cu^{2+}]^3[AsO_4^{3-}]^2 = 1\times 10^{-35}}[/tex]
which of the following has more atoms 3.14 g Cu or 1.10 g of H? Explain
Define symbol and compound with an exomple.
Write a balanced molecular equation describing each of the following chemical reactions.
(a) Solid calcium carbonate is heated and decomposes to solid calcium oxide and carbon
dioxide gas.
(b) Water vapor
Answer:
don't know..............
what is electrolysis
Answer:
Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell
describe two ways in which gases are similar to liquids in properties
Answer:
they have weak intermolecular forces
what is the balanced equation of 2HCl + Mg - MgCla + Ha
2HCl + Mg => MgCl2 + H2
