Answer:
Cathode rays are streams of electrons observed in discharge tubes. In 1897, British physicist J. J. Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, which was later named the electron. Cathode-ray tubes (CRTs) use a focused beam of electrons deflected by electric or magnetic fields to render an image on a screen.
Which term is used to describe the variety
of inheritable traits in a species?
Ecosystem diversity
Genetic diversity
Natural selection
Species diversity
So, Ecosystem Diversity is a term that describes how different habitats of organisms are. For example, the fact that our planet has deserts, tundras but also estuaries is a sign of the diversity of its ecosystems. Species diversity refers to the number of different species that inhabit a specific ecosystem or the whole biosphere; the more, the better for species diversity. Genetic diversity is the term we are looking for; it means the variation in genes (usually in one species) that leads to different inheritable traits (in members of the same species). For example eye color is an inheritable trait that showcases genetic diversity since there are many genes that determine a different color such as brown, blue, green etc. (even though the environment plays a role too). Finally, natural selection is a theory about the survival of the fittest due to competition. It relates to inheritable traits and their diversity but it does not describe them.
Which of the following involves a reaction in which energy is absorbed?
O A. An instant cold pack
O B. A car's engine
C. A chemical hand-warmer
O D. A campfire
What type of reaction is _CaCO3 and H2
Decomposition: A substance breaks down to smaller species.
What is the energy of an electron in the third energy level of hydrogen?
Answer:
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.
...
Energy Levels of Electrons.
Energy Level Energy
1 -13.6 eV
2 -3.4 eV
3 -1.51 eV
4 -.85 eV
f) How many neutrons are there in the nucleus of arsenic?
1. Neodymium
2. Selenium
3. Strontium
Explanation:
How many neutrons are there in the nucleus of arsenic?42 neutrons
The nucleus consists of 33 protons (red) and 42 neutrons (blue).
pls help me i really need help
Answer:
13. t = 1183 min and 0.50 M.
14. [tex]t_{1/2}=2.67x10^{-8}hr[/tex]
Explanation:
Hello!
13. In this case, according to the units, we infer this is a second-order reaction which has the following integrated rate law:
[tex]\frac{1}{[A]} =\frac{1}{[A]_0} +kt[/tex]
Which can be solved for the time as shown below:
[tex]t=\frac{ \frac{1}{[A]}-\frac{1}{[A]_0}}{k}[/tex]
Thus, we plug in the given concentrations and rate constant to obtain:
[tex]t=\frac{ \frac{1}{0.250M}-\frac{1}{0.850M}}{0.002387M^{-1}min^{-1}}\\\\t= 1183min[/tex]
For the second part, we proceed by using the same rate constant and the new initial concentration as follows:
[tex]\frac{1}{[A]} =\frac{1}{[A]_0} +kt\\\\\frac{1}{[A]} =\frac{1}{0.750M} +0.680M^{-1}min^{-1}*0.996min\\\\\frac{1}{[A]} =1.99,M[/tex]
[tex][A]=0.50M[/tex]
14. In this case, according to the units of the rate constant, we infer this is a zeroth-order reaction, therefore we compute the half-life has shown below:
[tex]t_{1/2}=\frac{[A]_0}{2k}[/tex]
Thus, we plug in to obtain:
[tex]t_{1/2}=\frac{2.696x10^{-6}M}{2*50.5M*hr^{-1}}[/tex]
[tex]t_{1/2}=2.67x10^{-8}hr[/tex]
Best regards!
A speed boat, at full throttle, can go 65.0 miles in 1.5 hours. What is the average speed of the boat?
The average speed = 43.33 miles per hours(mph)
Further explanationGiven
distance = 65 miles
time = 1.5 hours
Required
The average speed
Solution
The average speed : distance traveled divided by time taken or total distance divided by total elapsed time
Can be formulated :
avg speed = distance : time
avg speed = d : t
Input the value :
avg speed = 65 miles : 1,5 hours
avg speed = 43.33 miles per hours(mph)
Which is the correct molar mass for the compound h2SO4
Explanation: just add the atomic masses on the periodic table together for each atom.
Answer:Sulfuric acid
Explanation:because I said so
Consider the sodium borohydride reduction of camphor to isoborneol. A reaction was performed in which 1.000 g of camphor was reduced by an excess of sodium borohydride to make 0.661 g of isoborneol. Calculate the theoretical yield and percent yield for this reaction.
Answer:
m = 1.0164 g
% = 65.03%
Explanation:
First of all, we need to write the chemical reaction that is taking place here. We have the camphor being reduced to isoborneol:
C₁₀H₁₆O + NaBH₄ -----------> C₁₀H₁₈O + NaBH₂
We have a 1:1 mole ratio between Camphor and isoborneol, so, the moles of the camphor will be the same moles produced of isoborneol.
To get the theorical yield we need to calculate the theorical moles produced of isoborneol, then, the mass and compare it to the given mass. In that way we will get the %yield.
The Molar mass of camphor and isoborneol are:
MM C₁₀H₁₆O = (16*1) + (12*10) + 16 = 152 g/mol
MM C₁₀H₁₈O = (18*1) + (12*10) + 16 = 154 g/mol
The moles of camphor will be:
molesC₁₀H₁₆O = 1 / 152 = 0.0066 moles
The mass produced then of isoborneol should be:
mC₁₀H₁₈O = 0.0066 * 154
mC₁₀H₁₈O = 1.0164 gNow, the %yield would be:
% = (0.661 / 1.0164) * 100
% = 65.03%Hope this helps
Why is it important to know gas properties at STP?
Answer:
STP values are most often cited for gases because their characteristics change dramatically with temperature and pressure. One common definition of STP is a temperature of 273 K (0° Celsius or 32° Fahrenheit) and the standard pressure of 1 atm. Under these conditions, one mole of a gas occupies 22.4 L.
Can someone help me with this
Answer:
a
b
d
c
Explanation:
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee (so bot sees more so thinks it explain)
Number of liters in 0.50 moles of O2
Answer:
there are about 11.2 liters
A formula unit made with Na and unknown nonmetal "Z" has the formula, NaZ. Which element does "Z" represent?
GOOD REWARD
I will report those who gives random answers.
Answer:
3 mol AlCl₃.
Explanation:
Hello!
In this case, according to the specified reactants and products, it is possible to set up the following balanced chemical reaction:
[tex]Al(NO_3)_3+3NaCl\rightarrow 3NaNO_3+AlCl_3[/tex]
Whereas we evidence the 1:3 mole ratio between aluminum nitrate and sodium chloride; thus, since different moles were reacting, we need to identify the limiting reactant by computing the moles of AlCl₃ produced by each reactant as follows:
[tex]n_{AlCl_3}^{by\ Al(NO_3)_3}=4molAl(NO_3)_3*\frac{1molAlCl_3}{1molAl(NO_3)_3} =4molAlCl_3\\\\n_{AlCl_3}^{by\ NaCl}=9molNaCl*\frac{1molAlCl_3}{3molNaCl} =3molAlCl_3[/tex]
Thus, we infer that NaCl is the limiting reactant as it produces the fewest moles of AlCl₃; consequently the produced amount of this product is 3 mol.
Best regards!
Which of the following represents C3H8?
Among the given options the compound with the formula C₃H₈ is option C. It is an organic compound under named as propane.
What is propane?
Propane is an organic compound classified as a hydrocarbon with saturated carbon - hydrogen bonds. It's formula is C₃H₈. It contains 3 carbons and 8 hydrogens.
The two end carbons contains 3 hydrogens each and the middle carbon contains 2 hydrogens. They are all bonded through sigma bonding. The compound in A is C₅H₁₂ and in B, it is C₆H₁₄.
The formula of the compound in option D is C₅H₁₀. Hence, the skeleton showing the compound with the formula of C₃H₈ is option C.
To find more on propane, refer here:
https://brainly.com/question/24159489
#SPJ2
Nitrates are _____.
compounds made from carbon dioxide
used by plants to make protein
released into the atmosphere by respiration
are harmful to the environment
Answer:
used by plants to make protein
Explanation:
so B
Ways in which ions may form include
Answer:
Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions; by combination of ions with other particles; or by rupture of a covalent bond between two atoms in such a way that both of the electrons of the bond are left in association
The ways Ions may form includes the following
The addition of electrons to neutral atoms or moleculesThe removal of electrons from neutral atoms or molecules By combination of ions with other particlesWhen the number of protons does not equal the number of electrons in an atomMeaning of an IonAn ion can be defined as an atom or group of atoms possessing an electrical charge. Ions are of two types, they are : Anions which are negatively charged and Cations which are positively charged.
In conclusion, an ion can be formed by many ways, but a few has been listed above.
Learn more about ions : https://brainly.com/question/14511468
#SPJ2
Fill the plastic cup half full with room-temperature water, and drop in the whole tablet. Use a stopwatch to measure how long it takes the tablet to dissolve completely. Record your observation.
Answer:
it bubbles up and has a chemical reaction also releases co2
Explanation:
Hope it helps <3
Racecar driver Keimesha was in a race and accelerated from rest to 39 m/s by the time she reached the finish line. Keimesha’s car moved in a straight line and traveled from the starting line to the finish line in 6.0 seconds. What was the acceleration of the dragster?
Answer:
the acceleration of the racecar is 6.5 m/s²
Explanation:
Given;
initial velocity of the racecar, u = 0
final velocity of the racecar, v = 39 m/s
time of motion, t = 6.0 s
The acceleration of the racecar is calculated as;
[tex]a = \frac{v-u}{t} \\\\a = \frac{39-0}{6} \\\\a = \frac{39}{6} \\\\a = 6.5 \ m/s^2[/tex]
Therefore, the acceleration of the racecar is 6.5 m/s²
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide? (Hint: use the molar masses)
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
[tex]M_2O+H_2\rightarrow 2M+H_2O[/tex]
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
[tex]5.00gM_2O*\frac{1molM_2O}{(2*X+16)gM_2O}*\frac{2molM}{1molM_2O}*\frac{XgM}{1molM}=2.32gM[/tex]
Thus, we perform the operations in order to obtain:
[tex]\frac{10X}{(2X+16)}=2.32[/tex]
So we solve for x as shown below:
[tex]10X=2.32(2X+16)\\\\10X=4.64X+37.12\\\\X=\frac{37.12}{10-4.64}\\\\X= 6.93g/mol[/tex]
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!
In which state of matter are the particles at rest (not moving at all)?
none of these
solid
liquid
gas
Answer:
Solids for sure
particles of solid cant flow.
Answer:
B)Solids
Solids have tightly packed particles unlike liquids and gases whose particles can move freely but rate of movement is highest in gas while compared to water
Western art criticism unique in that
Answer:
they are a lot tougher and are expecting only greatness, sort of like theater critiques.
Explanation:
1. How many grams are there in 1.5 x 10^25 molecules of CO2?
Answer: 1.1 kg
Explanation:
Mw CO2 is 44g —> 6.02214076*10^23 molecules
1.5*10^25 molecules —> 1.1 kg
Calculate the kinetic energy of an electron ejected from a piece of sodium (Φ = 4.41x10–19 J) that is illuminated with 265 nm light.
in Joules
Answer:
Explanation:
Energy of falling radiation having wavelength of 265 nm
= h c / λ where h is plank's constant , c is velocity of light and λ is wavelength of radiation . Putting the values
Energy of light photon = 6.6 x 10⁻³⁴ x 3 x 10⁸ / 265 x 10⁻⁹
= .0747 x 10⁻¹⁷
= 7.47 x 10⁻¹⁹ J .
Work function of sodium is 4.41 x 10⁻¹⁹
So kinetic energy of ejected electron = energy of falling photon - work function
= 7.47 x 10⁻¹⁹ - 4.41 x 10⁻¹⁹
= 3.06 x 10⁻¹⁹ eV .
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide? (Use molar masses)
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
[tex]M_2O+H_2\rightarrow 2M+H_2O[/tex]
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
Thus, we perform the operations in order to obtain:
[tex]\frac{10X}{(2X+16)}=2.32[/tex]
So we solve for x as shown below:
[tex]10X=2.32(2X+16)\\\\10X=4.64X+37.12\\\\X=\frac{37.12}{10-4.64}\\\\X= 6.93g/mol[/tex]
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!
Apply: Click Reset. Set m to 1.0 kg, L to 2.0 m, g to 9.8 m/s2, and θ to –40 degrees. What is the maximum velocity of this pendulum? Show your work. (Hint: The exact height of the pendulum is now 0.468 m.)
Answer:
[tex]3.029\ \text{m/s}[/tex]
Explanation:
m = Mass of pendulum = 1 kg
L = Length of pendulum = 2 m
g = Acceleration due to gravity = [tex]9.8\ \text{m/s}^2[/tex]
h = Height of the pendulum = 0.468 m
[tex]\theta[/tex] = Angle of deflection = [tex]-40^{\circ}[/tex]
[tex]\cos\theta=\dfrac{L-h}{L}\\\Rightarrow h=L-L\cos\theta\\\Rightarrow h=L(1-\cos\theta)\\\Rightarrow h=2(1-\cos(-40))=0.468\ \text{m}[/tex]
The energy balance of the pendulum is as follows
[tex]mgh=\dfrac{1}{2}mv^2\\\Rightarrow v=\sqrt{2gh}\\\Rightarrow v=\sqrt{2\times 9.8\times 0.468}\\\Rightarrow v=3.029\ \text{m/s}[/tex]
The maximum velocity of this pendulum is [tex]3.029\ \text{m/s}[/tex].
Answer:
Max velocity = 3.03 m/s
Explanation:
Mgh = ½ mv2
(1 kg)(9.8 m/s2)(0.468 m) = ½ (1 kg) v2
2 x 4.5864 = ½ v2 x 2
√V2 = √9.1728
V = 3.03 m/s
I hope this helps!
please help me with this problem
the amount of reactants = the amount of products
N2 + 3H2 --> 2NH3
Practice: Balance each of the chemical equations below. (Some equations may already be in balance.) In the space to the right, classify the reaction as a synthesis, decomposition, single replacement, or double replacement reaction. A. AgNO3 + KCl ???? AgCl + KNO3 B. H2O + SO3 ???? H2SO4 C. KI + Cl2 ???? KCl + I2 D. NaHCO3 ???? Na2CO3 + H2O + CO2 E. Zn + HCl ???? ZnCl2 + H2 F. BaCl2 + Na2SO4 ???? BaSO4 + NaCl G. C3H8 + O2 ???? CO2 + H2O H. Al + CuCl2 ???? AlCl3 + Cu
Explanation:
A. AgNO3 + KCl --> AgCl + KNO3
Reaction is already balanced.
Type = Double Replacement
B. H2O + SO3 --> H2SO4
Reaction is already balanced.
Type = Synthesis
C. KI + Cl2 --> KCl + I2
Balanced Equation = 2KI + Cl2 --> 2KCl + I2
Type = Single Replacement
D. NaHCO3 --> Na2CO3 + H2O + CO2
Balanced Equation = 2NaHCO3 --> Na2CO3 + H2O + CO2
Type = Decomposition
E. Zn + HCl --> ZnCl2 + H2
Balanced Equation = Zn + 2HCl --> ZnCl2 + H2
Type = Single Replacement
F. BaCl2 + Na2SO4 --> BaSO4 + NaCl
Balanced Equation = BaCl2 + Na2SO4 → 2NaCl + BaSO4
Type = Double Replacement
G. C3H8 + O2 --> CO2 + H2O
Balanced Equation = C3H8 + 5O2 → 3CO2 + 4H2O
Type = Single Replacement
H. Al + CuCl2 --> AlCl3 + Cu
Balanced Equation = 2Al + 3CuCl2 → 2AlCl3 + 3Cu
Type = Single Replacement
PLEASE ANSWER QUICKLY!!!
Answer:
A and C
Explanation:
An ion dipole interaction exists between a molecule having a dipole and an ion. The positive end of the dipole interacts with a negative ion while the negative end of the dipole interacts with a positive ion.
If we look at the options listed, the H-H bond is non polar, hence it can not show ion-dipole interaction.
Similarly, the H-F bond is polar, but the negative end of the dipole (F) is made to interact with a sulphide(negative) ion which is incorrect.
Which of the following represent chemical processes? Which represent physical processes?
A). Calcium chloride dihydrate (CaCl2 * 2H2O) slowly heated in a crucible to become calcium chloride (anhydrous).
B). A hydrocarbon such as propane (C3H8) undergoes combustion to power a grill
C). A rock climber’s rope becomes frayed and turns the color of the rocks
D). A dog urinates on an air conditioner coil and the coil becomes corroded
Answer:
A). Calcium chloride dihydrate (CaCl2 * 2H2O) slowly heated in a crucible to become calcium chloride (anhydrous).
Dehyration is a physical process
B). A hydrocarbon such as propane (C3H8) undergoes combustion to power a grill
Combustion is a chemical process.
C). A rock climber’s rope becomes frayed and turns the color of the rocks
This is physical process
D). A dog urinates on an air conditioner coil and the coil becomes corroded
Corrsion is a chemical process.
Explanation:
The chemical process is combustion and corrosion i.e. B and D. The physical change has been the heating of calcium chloride, and fraying of rock i.e. A and C.
A chemical process has been given as the reaction in which the composition of the sample changes. It has been an irreversible process.
A physical process has been described as a change in the physical properties of substances. It is a reversible process.
The following reaction can be given as:
A. The reaction between calcium chloride and water has been mediated by heating. It is a reversible process and does not change the chemical composition. It is a physical process.
B. The combustion results in the change in the chemical constituents of propane. It is a chemical process.
C. There has been no change in the chemical composition of materials. It has been a physical process.
D. The corrosion has resulted from the chemical change in the iron. It has been a chemical process
Thus, the chemical process is combustion and corrosion. The physical change has been the heating of calcium chloride, and fraying of rock.
For more information about the chemical process, refer to the link:
https://brainly.com/question/1286014