Answer:
6 and 8
Explanation:
what is physical change and chemical change
Answer:
Physical change occur when objects or sub undergo a change that does not change their chemical composition.
Chemical change us a permanent change which occur when a substance combined with another to form a new substances.
what does an atomic emission spectrum look like if the electrons energy levels in an atom were not quantizied
a. lines would be shifted into the ultraviole region
b. there would be fewer lines
c. there will be more lines
d. the spectrum would be constnuous
Answer: The spectrum would be continuous
Explanation:
Atomic transitions allow us to find that the correct answer to what would happen if there was no quantization is:
d. the spectrum would be continous
In the models of atoms the correct explanation for the energy was given by Planck, by establishing that the energy of an electron is:
E = h ν
Where E is the energy, h the Planck constant and ν the frequency.
Therefore a transition occurs as the jump of an electron from one level to another
ΔE = E₂ - E₁
In all atomic models the levels are discrete, so the jumps are also discrete.
If the levels were continuous, the energy difference between the lines disappears and we have a continuous emission spectrum.
Let's review the different answers:
a. False. The lines disappear
b. False. This for if the separation between levels increases, which is the opposite process to the one analyzed.
c. False. The lines disappear
d) True. The spectrum is a continuum without any separation.
In conclusion, using the atomic transitions we find that the correct answer for what would happen if there was no quantization is:
d. the spectrum would be constnuous
Learn more here: brainly.com/question/19426165
Does anyone know the answer to this I need it ASAP
Girls are usually completely physically mature by _____ years old.
A.
17
B.
19
C.
14
D.
21
Please select the best answer from the choices provided. Anyone know for EDGE
A
B
C
D
Answer:
a 17 bc it is how it works
Girls are usually completely physically mature by 18 years old.
What is puberty ?Puberty refers to the physical transformation of a child's body into an adult one capable of fertile reproduction.
In girls puberty generally attains before two years earlier than the boys. And the exact age of the girls to attain puberty is in between the age of 10 to 14.
Hence the age of girls to attain puberty is 14.
To know more about puberty, visit the below link:
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#SPJ2
A boy swings a rubber ball attached to a string over his head in a horizontal, circular path. The piece of string is 1.15 m long and the ball makes 137 complete turns each minute. What is the tangential velocity of the ball
Answer:
v = 16.49 m/s
Explanation:
Given that,
Length of the string, l = 1.15 m
The ball makes 137 complete turns each minute.
We know that, 1 turn = 6.28 rad
137 turns = 860.79 rad
1 min = 60 s
[tex]\omega=\dfrac{860.79\ rad}{60\ s}\\\\=14.34\ rad/s[/tex]
We need to find the tangential velocity of the ball. It can be given by
[tex]v=r\omega\\\\=1.15\times 14.34\\\\v=16.49\ m/s[/tex]
So, the tangential velocity of the ball is 16.49 m/s.
How are the isotopes of an element different from one another ?
Which two characteristics are associated with metals
Answer:
high electrical and thermal conductivity
Answer:
Metals donate electrons.
They are good conductors of heat and electricity.
By examining the diagram, which of the following is NOT needed for photosynthesis:
O sunlight
O carbon dioxide
O water
oxygen
Order the elements from smallest to largest atomic number
the largest is francium, Z=87 , or caesium, Z=55 ; and the smallest is definitely helium, Z=2 .
Explanation:
make me Brainliest
What do you call the meetings of two planets/objects as seen from the earth? hurrry ASAP!!!!!
Answer:
It's called "Great conjunction"
Which element forms an ionic compound when it reacts with lithium?
1. K
2. Fe
3. Kr
4. Br
When an atom has a positive charge, it has ____ electrons
a. gained
b. shared
c. loss
Answer:lossed
Explanation:
Predict the products of the following reaction:
RbNO2 +BaCO3->
Answer:
2RbNO2 + BaCO3 → Rb2CO3 + Ba(NO2)2
Explanation:
The balanced reaction equation is shown below;
2RbNO2 + BaCO3 → Rb2CO3 + Ba(NO2)2
This reaction is possible because the reduction potential of Rb is -2.98V while that of Ba is –2.92 V. Hence Rb can displace Ba from its salt solution.
The equation is balanced since the number of atoms of each element on the left and right hand sides of the reaction equation are equal.
The products for the reaction of Rubidium nitrite and Barium carbonate has been Barium nitrite and Rubidium carbonate.
Rubidium nitrite has been the binary ionic compound found to be acidic in nature. While barium carbonate has been the basic salt with the potency to be poisonous to humans.
The reaction between an acid and a base has been the neutralization reaction with the formation of salt and water. The reaction between rubidium nitrite and barium carbonate will be:
[tex]\rm 2\;RbNO_2\;+\;BaCO_3\;\rightarrow\;Rb_2CO_3\;+\;Ba(NO_2)_2[/tex]
The reaction has been the displacement reaction with the tendency to displacement.
For more information about displacement reaction, refer to the link:
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Show your work with good use of units, rounding, and significant figures. [Hint: it is good practice to show the value of your answer before you round off to the final answer with the correct significant figures!]
(7 points) A solution was prepared by dissolving 18.00 g of glucose in 150.0 g of water. The molar mass of glucose is 180.15 g/mol. The boiling point elevation constant for water is 0.512 °C•kg/mol.
What is the molality of the solution?
What is the resulting solution's new boiling point?
Answer:Boiling point of a solution is found to be 100.34
o
C. Boiling point of pure
water is 100
o
C.
The elevation in the boiling point ΔT
b
=100.34−100=0.34
o
C.
12 gm glucose (molecular weight 180 g/mol) is dissolved in 100 gm water.
The number of moles of glucose =
180g/mol
12g
=0.0667mol
Mass of water =100g×
1000g
1kg
=0.100kg
Molality of solution m=
0.100kg
0.0667mol
=0.667mol/kg
The elevation in the boiling point ΔT
b
=K
b
×m
0.34
o
C=K
b
×0.667mol/kg
K
b
=0.51
o
Ckg/mol
The molal elevation constant for water is 0.51
o
Ckg/mol.
Explanation:
Aluminum bromide and chlorine gas react to
form aluminum chloride and bromine gas.
Answer:
ok
Explanation:
Please help with this I do not under stand
Answer:
See below:
Explanation:
The grasshopper doesn't require an exchange of gasses (air) using a circulatory system because the gasses directly reach its cell's from the "air sacs" which spread out into tiny tubes close to each cell.
What are three physical properties that could be used to identify gold?
Answer:
solid ,hard, not see through
Explanation:
Answer:
There are many properties out there, so three include bright yellow color, luster shine, and the maleability that determines the durability.
500 mL solution of calcium chloride with a concentration of 0.75 mol/L. The mass of solute needed to make this solution is ___ ___ ___ ___ g.
Answer:
41.63g
Explanation:
Given parameters:
Volume of CaCl₂ = 500mL = 0.5L
Concentration = 0.75mol/L
Unknown:
Mass of the solute needed = ?
Solution:
The mass of the solute can be derived using the expression below;
Mass = number of moles x molar mass
But,
Number of moles = Concentration x Volume
So;
Mass = Concentration x Volume x molar mas
Molar mass of CaCl₂ = 40 + 2(35.5) = 111g/mol
Mass = 0.75 x 0.5 x 111 = 41.63g
A beaker containing 6.32 moles of PBr3, contains___
molecules of PBrz.
A) 1712.7
B) 3.1 x 10^24
C) 3.8 x 10^24
D) 271
Answer:
3.8 x 10²⁴molecules
Explanation:
Given parameters:
Number of moles = 6.32moles
Unknown:
Number of molecules = ?
Solution:
The number of moles can be used to derive the number of molecules found within a substance.
Now,
1 mole of substance contains 6.02 x 10²³ molecules
6.32 mole of PBr₃ will contain 6.32 x 6.02 x 10²³ = 3.8 x 10²⁴molecules
3 Which statement is not correct?
А: When a base reacts with an ammonium salt, ammonia is given off
B: When an acid reacts with a base, neutralisation takes place.
C: When an acid reacts with a carbonate, carbon dioxide is given off.
D: When the acidity of a solution increases, the pH increases.
Answer:
D: When the acidity of a solution increases, the pH increases.
Explanation:
It is totally wrong to assert that when the acidity of a solution increases, the pH of the solution will increase
The right answer is that when the acidity of a solution increases, the pH value decreases.
The pH scale records the level of acidity and basicity of a substance. It runs from 1 to 14From 7 to 14 signifies increasing basicity As the acidity of a substance increases, the pH value reduces. For acids 1 is the highest acidity levels.which elements are cations and anions
Lithium
Sodium
Beryllium
aluminum
phosphorus
oxygen
fluorine
Answer:
Lithium,sodium, beryllium, aluminum form cations and the rest form anions
Explanation:
i think the question should be rephrased as 'which elements form cations".
What is the condensation AND freezing point of water C AND F!!
Answer:
Condensation 212F or 100C, Freezing 32F or 0C
Explanation:
Condensation 212 degrees Fahrenheit or 100 degrees Celsius.
Freezing point 32 degrees Fahrenheit or 0 degrees Celsius.
Evaluate each statement and determine which statement is not a determining factor in the formation of intrusive igneous rocks? Group of answer choices Magma cools very fast beneath the Earth's surface None of these Slow cooling allows large crystals to grow The Earth's interior has very high temperatures
Answer: The statement that is not a determining factor in formation of intrusive igneous rocks is 'None of the above' and Magma cools very fast beneath the Earth's surface.
Explanation:
Rocks are naturally occurring solid materials that are made up of different types of minerals which affects it's texture and colours. The three main types of rocks are:
--> sedimentary rocks,
--> metamorphic rocks and
--> igneous rocks.
Igneous rocks are formed from the crystallization and solidification of hot molten rocks which originates from deep within the earth. Depending on where the molten rock solidifies, the igneous rock is divided into two, namely:
--> intrusive igneous rock and
--> extrusive igneous rock.
The INTRUSIVE IGNEOUS rocks are formed within or deep beneath the earth surface when the hot magma SLOWLY cools over millions of years until it solidifies. The slow cooling allows large crystals to grow.
Therefore the statements (None of the above and Magma cools very fast beneath the Earth's surface) are not a determining factor.
If the rate of formation of ammonia gas in haber bosch 2.5x10-4 mol/l-1/s-1 then rate of consumption of n2 gas during process equals... mol/l-1/s-1
A)-2.5x10-4
B) -1.25x10-4
C)-3.75x10-4
D)-5x10-4
Can somebody help me out i am stressed
Rate of consumption of N₂ = - 1.25 x 10⁻⁴
Further explanationThe reaction rate (v) shows the change in the concentration per unit time.
[tex]\tt rate=\dfrac{concentration(M)}{time(s)}[/tex]
The rate reaction for Haber Bosch :
N₂(g)+3H₂(g)⇒2NH₃(g)
From equation, mol ratio N₂ : NH₃ = 1 : 2, so
the rate of formation of ammonia = 2 x the rate of consumption of nitrogen.
Given
the rate of formation of ammonia gas : 2.5x10⁻⁴ M/s
the rate of consumption of nitrogen :
[tex]\tt \dfrac{2.5\times 10^{-4}}{2}=1.25\times 10^{-4}[/tex]
The sign negative for consumption : -1.25 x 10⁻⁴ M/s
or we can use another way:
Rate of formation of NH₃ = reaction rate x coefficient of NH₃
2.5 x 10⁻⁴ = reaction rate x 2
reaction rate = 1.25 x 10⁻⁴
Rate of consumption of N₂ = reaction rate x coefficient of N₂
Rate of consumption of N₂ = 1.25 x 10⁻⁴ x 1
Rate of consumption of N₂ = 1.25 x 10⁻⁴
Think about your morning from when you wake up until you arrive at school. Describe the forms of energy you encounter or use during that time. (Use types of energy like electrical, mechanical, thermal, etc)
Answer:
When sleeping the energy exhibited is Potential energy. When I wake up and I’m preparing for the day I use kinetic energy which is the energy exhibited during motion.
Eating before leaving the house means I used chemical energy for replenishment of nutrients to aid the performance of more activities for the day. The food eaten and the physical activities also give rise to thermal energy which is why we sweat.
What is the percent of Li in
Li3N?
(Li = 6.94 amu, N = 14.01 amu)
Answer:
The percentage by mass of lithium in one mole of Li₃N is approximately 59.78%
Explanation:
The given compound is Li₃N
The atomic mass of lithium, Li = 6.94 amu
The atomic mass of nitrogen, N = 14.01 amu
Therefore by definition, we have;
The mass of one mole of lithium, Li = 6.94 g
The mass of one mole of nitrogen, N = 14.01 g
One molecule of Li₃N contains 3 atoms of lithium, Li and 1 atom of nitrogen, N
The mass of one mole of Li₃N = The molar mass of Li₃N = 3 × The mass of one mole of lithium + The mass of one mole of nitrogen
∴ The mass of one mole of Li₃N = 3 × 6.94 g + 14.01 g = 34.83 g
The percentage by mass of lithium, Li, in one mole of Li₃N = 3×6.94/(34.83) × 100 ≈ 59.78%
The percentage by mass of lithium in one mole of Li₃N ≈ 59.78%.
What information do the coefficients of a balanced equation give about the
reactants?
A. The coefficients tell what oxidation states the atoms are in.
B. The coefficients give the molar ratio of the reactants.
C. The coefficients give the gram ratio of the reactants.
D. The coefficients tell what the molar mass of each reactant is.
Answer:
B. The coefficients give the molar ration of the reactants
Explanation:
DO ANY OF YALL KNOW THIS?????
1. Why do we need to use the mole to count atoms? (2pts)
2. What is the Molar mass of the following? Show your work
a. H2O2 (4pts)
b. C2H6 (4pts)
Answer:
1.mole allows us to weigh convenient amounts of material containing known numbers of atoms; i.e., it allows us to count atoms
2. H202 :34.0147 g/mol
C2H6: 30.07 g/mol
What type of ion would radium (88Ra) become when forming an ionic compound, and what would the oxidation number be?
A) a cation with a +2 charge
B) a cation with a -2 charge
C) an anion with a +1 charge
D) an anion with a -1 charge
Answer:
The correct option is A
Explanation:
Radium is an atom with the atomic number of 88. It is a metal found in group 2 of the periodic table; meaning that it has two valence electrons in it's outermost shell. As a metal that wants to form an ionic compound, radium would have to lose these two valence electrons to become a divalent positively charged cation (Ra²⁺). Thus, the correct option is A
What is the pH of .000062 M NaOH solution
Answer:
4.207
Explanation:
PH = -log .000062=4.207