umm explanation pls so i answee
Which describes a speed?
O A. Moving 8 meters in 2 seconds
O B. Falling down at 100 miles/hr
O C. Moving north at 40 km/hr
O D. Speed changing from 2 km/hr to 5 km/hr
An overhead view of two people at the start of a maze. The person in a purple shirt has a line running forward, right, backward, right, forward, ending with an arrowhead pointing to a large gold star. The person in a green shirt has a line running forward, right, backward, right, forward, right, backward, right, forward, ending with an arrowhead pointing to a small gold star.
Zamir and Talia raced through a maze. Zamir walked 2 m north, 2 m east, 4 m south, 2 m east, 4 m north, 2 m east, 3 m south, 4 m east, and 4 m north. Talia walked 2 m north, 6 m east, 3 m south, 4 m east, and 4 m north.
Compare their distances:
Zamir walked
meters and Talia walked
Answer:
Zamir walked
27
meters and Talia walked
19
meters.
Explanation:
27 and 19
Answer:
zamir:27 Talia:19
Explanation:
i got it right on my test :)
Describe how this instrument works.
Operation:
Answer:
Microscope
Explanation:
Answer:
its a telescope you see stars or plants
Explanation:
Hat is the answer for this
Answer:
C
Explanation:
Answer:
I think is A
Explanation:
Hope it helps
True or False: Scientists use what they know about the properties of different molecules to separate mixtures. *
Answer:
True
Explanation:
Mixtures are substances with indefinite composition. They consist of two or more elements and or compounds in any proportion by mass.
Their constituents retain their identities i.e. physical properties are retained. Their constituents reacts differently to changed conditions. They can easily be separated into constituents by physical methods.From these properties we can clearly identify that to separate mixtures, we use the differences in the chemical properties of the constituents of the mixtures.
410X
412
412
410
183
186
183R
Which two are isotopes?
10 POINTS PLS HELP
Combustion occurs when _____.
oxidation reactions are very slow
oxidation reactions are so fast the substance catches fire
oxygen is removed from another substance
machines use chemical energy to do work
Answer: oxidation reactions are so fast the substance catches fire
Explanation:
Answer:
When oxidation reactions are so fast the substance catches fire
Explanation:
because i am big bwain
lead(II) nitrate, Pb(NO3)2, and potassium iodide, KI
net ionic equation:
Answer:
Pb²⁺ (aq) + 2I⁻ (aq) → PbI₂ (s)
General Formulas and Concepts:
Solubility RulesReaction PredictionExplanation:
Step 1: RxN
Pb(NO₃)₂ (aq) + KI (aq) → PbI₂ (s) + KNO₃ (aq)
Step 2: Balance RxN
Pb(NO₃)₂ (aq) + 2KI (aq) → PbI₂ (s) + 2KNO₃ (aq)
Step 3: Ionic Equations
Total Ionic Equation:
Pb²⁺ (aq) + 2NO₃⁻ (aq) + 2K⁺ (aq) + 2I⁻ (aq) → PbI₂ (s) + 2K⁺ (aq) + 2NO₃⁻ (aq)
Cancel out spectator ions.
Net Ionic Equation:
Pb²⁺ (aq) + 2I⁻ (aq) → PbI₂ (s)
Determine the wavelength of the energy that needs to be absorbed for a 3p electron in chlorine to be promoted to the 4s subshell. Assume that Zeff=6 for a chlorine atom.
Answer:
The wavelength of the energy that needs to be absorbed = 52.36 nm
Explanation:
For this study;
Let consider the Rydgberg equation from Bohr's theory of atomic model:
i.e.
[tex]\dfrac{1}{\lambda} = R_H (Z^*)^2( \dfrac{1}{n_1^2}-\dfrac{1}{n_2^2})[/tex]
where
Z* = effective nuclear charge of atom = Z - σ = 6
n₁ = lower orbit = 3
n₂ = higher orbit = 4
[tex]R_H[/tex] = Rydyberg constant = 1.09 × 10⁷ m⁻¹
λ = wave length of the light absorbed
∴
[tex]\dfrac{1}{\lambda} = 1.09 \times 10^7}(6)^2( \dfrac{1}{3^2}-\dfrac{1}{4^2})[/tex]
[tex]\dfrac{1}{\lambda} = 1.09 \times 10^7}(36)( \dfrac{1}{9}-\dfrac{1}{16})[/tex]
[tex]\dfrac{1}{\lambda} = 392400000\times0.0486111111[/tex]
[tex]\dfrac{1}{\lambda} =19075000[/tex]
[tex]\lambda = \dfrac{1}{19075000}[/tex]
[tex]\lambda = \dfrac{1}{1.91\times 10^7 \ m^{-1}}[/tex]
[tex]\lambda = 5.236 \times 10^{-8} m[/tex]
[tex]\lambda = 52.36 \times 10^{-9} m[/tex]
[tex]\lambda = 52.36\ n m[/tex]
Therefore, the wavelength of the energy that needs to be absorbed = 52.36 nm
Which is the Lewis structure for H3PO4? An upper P is single bonded above to an O, and to the left, right, and below to an O single bonded to an H. The O above the P has three pairs of dots to the left, above, and below; the O's to the sides have pairs of dots above and below, and the O below the P has pairs of dots right and left. A central upper P is single bonded left, right, above, and below to upper Os. The O above the P is single bonded to upper H on the left and the right, and has two electron dots above it. The O below the P is single bonded to an H below, and has pairs of electron dots to the left and right. A central upper P is double bonded to an O above, and single-bonded to an upper O single-bonded to an upper H to the left and the right. The O above the P has three pairs of electron dots, to the left, above, and to the right; the O's to the right and left have pairs of dots above and below. A central upper P is bonded to an upper H above, an upper O below, and upper O's bonded to upper H's to the left and the right. The O below the P has three pairs of electron dots, to the left, right, and below; the other two O's have pairs of dots above and below. A central upper P is double bonded to an O above, and single-bonded to an upper O single-bonded to an upper H to the left and the right. The O above the P has three pairs of electron dots, to the left, above, and to the right; the O's to the right and left have pairs of dots above and below.
Answer:
It is A.
Explanation:
I took the test.
The Lewis structure shows the arrangement of valence electrons in H3PO4.
The Lewis structure gives us a picture of the number of valence electrons in a molecule. This is because, in a Lewis structure, the electrons in the molecule are shown as dots. A single line may be used to show shared electrons in a covalent bond.
The correct Lewis structure of H3PO4 is an upper P is single bonded above to an O, and to the left, right, and below to an O single bonded to an H. The O above the P has three pairs of dots to the left, above, and below; the O's to the sides have pairs of dots above and below, and the O below the P has pairs of dots right and left.
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How many milliliters of a 3.4 M NaCl solution would be needed to prepare each solution?
a. 45 mL of a 0.10 M solution:
mL
b. 330 mL of a 0.074 M solution:
mL
Answer:
a. Approximately [tex]1.3\; \rm mL[/tex].
b. Approximately [tex]7.2\; \rm mL[/tex].
Explanation:
The unit of concentration "[tex]\rm M[/tex]" is equivalent to "[tex]\rm mol \cdot L^{-1}[/tex]", which means "moles per liter."
However, the volume of both solutions were given in mililiters [tex]\rm mL[/tex]. Convert these volumes to liters:
[tex]\displaystyle 45\; \rm mL = 45\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.045\; \rm L[/tex].
[tex]\displaystyle 330\; \rm mL = 330\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.330\; \rm L[/tex].
In a solution of volume [tex]V[/tex] where the concentration of a solute is [tex]c[/tex], there would be [tex]c \cdot V[/tex] (moles of) formula units of this solute.
Calculate the number of moles of [tex]\rm NaCl[/tex] formula units in each of the two solutions:
Solution in a.:
[tex]n = c \cdot V = 0.045\; \rm L \times 0.10\; \rm mol \cdot L^{-1} = 0.0045\; \rm mol[/tex].
Solution in b.:
[tex]n = c \cdot V = 0.330\; \rm L \times 0.074\; \rm mol \cdot L^{-1} = 0.02442\; \rm mol[/tex].
What volume of that [tex]3.4\; \rm M[/tex] (same as [tex]3.4 \; \rm mol \cdot L^{-1}[/tex]) [tex]\rm NaCl[/tex] solution would contain that many
For the solution in a.:
[tex]\displaystyle V = \frac{n}{c} = \frac{0.0045\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0013\; \rm L[/tex].
Convert the unit of that volume to milliliters:
[tex]\displaystyle 0.0013\; \rm L = 0.0013\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 1.3\; \rm mL[/tex].
Similarly, for the solution in b.:
[tex]\displaystyle V = \frac{n}{c} = \frac{0.02442\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0072\; \rm L[/tex].
Convert the unit of that volume to milliliters:
[tex]\displaystyle 0.0072\; \rm L = 0.0072\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 7.2\; \rm mL[/tex].
Which is a valid reason why total dissolved solids (TDS) cannot be accurately calculated by conductivity alone?
Global warming has significantly increased the conductivity of water.
Big blobs of algae do not conduct electricity.
Fish poop changes the conductivity.
Ionic compounds may behave differently based on ion characteristics (e.g. charge or size).
Some dissolved solids may be nonelectrolytes.
Answer:
The correct option is the last option (Some dissolved solids may be nonelectrolytes)
Explanation:
Total dissolved solids (TDS) cannot be calculated by conductivity alone because conductivity involves ionic charges and there are solids that dissolve in water but do not carry ionic charges (and thus form non-electrolytes). Examples include sucrose (common sugar) and glucose. These two solids will dissolve in water but would not form ions that will carry ionic charges which are responsible for conductivity. Thus, if TDS only depends solely on conductivity, then a solution that contains dissolved sucrose will be wrongly accounted for as the sucrose will be omitted from the dissolved substances.
A valid reason why total dissolved solids (TDS) cannot be accurately
calculated by conductivity alone because some dissolved solids may be
non-electrolytes.
Conductivity means the ability of electric current to pass through a
substance and an electrolyte has a high conductivity when dissolved in
water.
Dissolved solids can't be measured by conductivity because not all
dissolved solids are electrolytes.
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J.J. Thomson's plum pudding model of the atom followed the discovery of
A)
negatively charged particles with a very small mass.
B)
positively charged particles with a very large mass.
0)
negative electrons that revolved around a positive nucleus.
D)
positively charged protons that were contained in a concentrated area.
J.J. Thomson's plum pudding model of the atom followed the discovery of negatively charged particles with a very small mass. Thus, the correct option for this question is A.
Who was J. J. Thomson?J.J. Thomson was a British physicist who discovered sub-atomic particles known as electrons within an atom. He also announced that atoms are made up of smaller components.
The plum pudding model is defined by Thomson in order to demonstrate that negatively charged sub-atomic particles known as electrons are surrounded by a volume of positively charged particles known as protons. It is one of the historical scientific model of the atom that governs all sorts of properties of sub-atomic particles.
Therefore, "negatively charged particles with a very small mass" is the discovery that follows J.J. Thomson's plum pudding model of the atom. Thus, the correct option for this question is A.
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Regional Metamorphism occurs when great masses of rock are exposed to pressure. What does this typically form?
Answer:
Gneiss forms by regional metamorphism from both high temperature and pressure. Quartzite and marble are the most commonly used metamorphic rocks.
22. In 4f12, the 12 stands for the
The 12 stands for the number of electrons that fill the f orbital
Further explanationIn an atom there are levels of energy in the shell and sub shell
This energy level is expressed in the form of electron configurations.
Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f. The maximum number of electrons for each sub shell is
• s: 2 electrons
• p: 6 electrons
• d: 10 electrons and
• f: 14 electrons
4f¹² :
4 : number of shell
12 : the number of electrons that fill the f orbital
the layering of rock horizontally is for the __________ only.
A. relative age
B. same age
C. absolute age
Answer:
A
Explanation:
The correct chemical formula for aluminum (Al+3) plus chlorine (Cl-1) is what.
Answer:
AlCl₃
General Formulas and Concepts:
Elemental ChargesReading a Periodic TableExplanation:
Step 1: Define
Al³⁺ and Cl¹⁻
Step 2: RxN
Al³⁺ (s) + Cl¹⁻ (g) → AlCl₃
Need to have the same amount of charge (should add to 0)We need 3 Cl's to balance the positive 3+ charge3(-1) for Cl + 1(3+) for Al = 0Answer:
The answer is: AlCl₃
Hope this helped :)))
Explanation:
Consider the two electron arrangements for neutral atoms A and B. What is the atomic number of A?
A - 1s?, 2s 2p6,35
B - 1s2, 2s 2p, 5s
Boron has two isotopes. Boron-10 which has a mass of 10.0129 and Boran-11 with a mass of 11.0093 occurs 52.69% of the time and B - 11 47.31% of the time. What is the average atomic mass of boron?
Help me
Answer:
Copper, a metal known since ancient times, is used in electrical cables and pennies, among other things. ... Calculate the average atomic mass of copper. ... The atomic masses of the two stable isotopes of boron 10B (19.78%) and 11B (80.22%) are 10.0129 amu ... (.1978)(10.0129 amu) + (.8022)(11.0093 amu) =10.81 amu.
Explanation:
I hope I help :)
Calculate the following quantity: molarity of a solution prepared by diluting 45.45 mL of 0.0404 M ammonium sulfate to 550.00 mL. M solution
Answer:
[tex]M_2=3.34x10^{-3}M[/tex]
Explanation:
Hello!
In this case, since a dilution process implies that the moles of the solute remain the same before and after the addition of diluting water, we can write:
[tex]M_1V_1=M_2V_2[/tex]
Thus, since we know the volume and concentration of the initial sample, we compute the resulting concentration as shown below:
[tex]M_2=\frac{M_2V_2}{V_1} =\frac{45.45mL*0.0404M}{550.00mL}\\\\M_2=3.34x10^{-3}M[/tex]
Best regards!
How many electrons are in the nucleus of an atom with an atomic number of
16?
O None. Electrons are not in the nucleus
08
O 16
O 32
Answer:
None. Electrons are not in the nucleus.
Explanation:
We know that an atom consist of electrons, protons and neutrons. Neutrons and protons are present inside the nucleus while electrons are present out side the nucleus. Electron has a negative charge and is written as e⁻. The mass of electron is 9.10938356×10⁻³¹ Kg . While mass of proton and neutron is 1.672623×10⁻²⁷Kg and 1.674929×10⁻²⁷ Kg respectively.
Symbol of proton= P⁺
Symbol of neutron= n⁰
The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons. The umber of protons and electrons are always equal to make the atom electrically neutral .
The atom having atomic number 16 have 16 electrons and these electrons are present out side the nucleus.
What causes your skin to feel warm when it is in the sun on a summer day?
A Particles in the atmosphere reflect energy from the Sun downward.
B Hot particles from the Sun still carry some heat when they reach your skin.
C The solar wind carries heated air from the Sun's atmosphere to Earth's surface.
D The Sun radiates energy that passes through space and the atmosphere to your skin.
Answer:
idek akxkkwskkd nwkdkekekd
5. Psilocybin is made of C 50.70%, H 6.03%, N 9.86%, 22.51%, P 10.90%. a. Find the empirical formula.
The empirical formula : C₁₂H₁₇N₂O₄P
Further explanationThe empirical formula is the smallest comparison of atoms of compound =mole ratio of the components
The principle of determining empirical formula
Determine the mass ratio of the constituent elements of the compound. Determine the mole ratio by by dividing the percentage by the atomic massC
[tex]\tt \dfrac{50.7}{12}=4.225[/tex]
H[tex]\tt \dfrac{6.03}{1}=6.03[/tex]
N[tex]\tt \dfrac{9.86}{14}=0.704[/tex]
O[tex]\tt \dfrac{22.51}{16}=1.407[/tex]
P[tex]\tt \dfrac{10.9}{31}=0.352[/tex]
Divide by the smallest mole ratio(0.352)
C : H : N : O : P
[tex]\tt C\rightarrow \dfrac{4.225}{0.352}=12[/tex]
[tex]\tt H\rightarrow \dfrac{6.03}{0.352}=17[/tex]
[tex]\tt N\rightarrow \dfrac{0.704}{0.352}=2[/tex]
[tex]\tt O\rightarrow \dfrac{1.407}{0.352}=4[/tex]
[tex]\tt P\rightarrow \dfrac{0.352}{0.352}=1[/tex]
Naming inconic compounds and lots of iconic naming
if you just look up the answer it comes up btw!!
have a great day
Just wanted to know what the response time is :)
Help with 3.A and B image provided below
a. P=0.971 atm=737.6 mmHg
b. n=2.88 x 10⁻³
Further explanationDalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases
[tex]\tt P_T=P_1+P_2+..P_n[/tex]
A. vapor pressure of water at 22.5 = 20.4 mmHg
Pt=P H₂ + P H₂O
758 = P H₂ + 20.4
P H₂=737.6 mmHg=0.971 atm
B.Ideal gas Law = PV=nRT
P = 0.971 atm
V = 72 ml = 0.072 L
R = 0.082 L/atm mol
T = 22.5 + 273.15 =295.65
[tex]\tt n=\dfrac{0.971\times 0.072}{0.082\times 295.65}=2.88\times 10^{-3}[/tex]
nitric acid, HNO3, and calcium hydroxide, Ca(OH)2
net ionic equation:
Answer:
2H⁺ (aq) + 2OH⁻ (aq) → 2H₂O (l)
General Formulas and Concepts:
Solubility RulesStrong Acids/BasesExplanation:
Step 1: RxN
HNO₃ (aq) + Ca(OH)₂ (aq) → Ca(NO₃)₂ (aq) + H₂O (l)
Step 2: Balance RxN
2HNO₃ (aq) + Ca(OH)₂ (aq) → Ca(NO₃)₂ (aq) + 2H₂O (l)
Step 3: Ionic Equations
Total Ionic Equation:
2H⁺ (aq) + 2NO₃⁻ (aq) + Ca²⁺ (aq) + 2OH⁻ (aq) → Ca²⁺ (aq) + 2NO₃⁻ (aq) + 2H₂O (l)
Cancel out spectator ions.
Net Ionic Equation:
2H⁺ (aq) + 2OH⁻ (aq) → 2H₂O (l)
How did you organize the tiles in part A? Describe the method that you used.
Periodic table of numbers tiles
Answer:
I ordered the tiles from left to right and top to bottom as the numbers kept increasing. The tiles were also organized based on the color and shape that they were. The tiles with the same color and shape were arranged in the same column.
Explanation:
In the modern periodic table, the elements are listed in order of increasing atomic number and elements having similar chemical properties naturally line up in the same column (group).
PLEASE HURRT I NEED HELP ASAP !!!!!!!!!!!!!!
Answer:
I think its b
Explanation:
well because thermal energy its connected to kidnetic energy
2. Which test for iron(II) ions is conclusive
Answer:
please brainlist answer
Explanation:
The addition of K 3 Fe(CN) 6 to a solution causes the formation of a deep blue precipitate which indicates that iron(II) ions are present.
The conclusive test for iron(II) ions is the test by the use of potassium hexacyanoferrate III solution.
In qualitative analysis certain reagents are used to test for the presence of certain cations or anions. Those reagents react in a certain way with those reagents. Usually, a positive test may involve a color change, formation of a precipitate or evolution of a gas.
In the case of iron(II) ions, potassium hexacyanoferrate III solution is used in the conclusive qualitative test for the ion. A positive test involves the appearance of a deep blue precipitate.
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