Answer: its b hope this helps.
Explanation:
Chemicals that control weeds are called
A. acaricides.
B. herbicides.
C. insecticides.
D. pesticides.
Answer:
The answer is D
Explanation:
because insecticides are used for insects but pesticides are used to kill off unwanted plants
Answer:
B. herbicides
Explanation:
it kills weeds.
A compound with a formula mass of 45.08 g/mol is found to be 85.64% Carbon and the remainder Hydrogen. Find the molecular formula:
A sample of wax requires heat to melt and become a liquid. What type of process is this?
Question 12 options:
A)
Deposition
B)
Sublimation
C)
Exothermic
D)
Endotherm
Answer:
D) Endothermic
Explanation:
An endothermic reaction absorbs heat. In this case, the wax absorbs the heat and it melts.
Also, I took the exam and I got it right.
Answer:
Endothermic is correct
true or false the human body system works together to maintain
Answer:
Im pretty sure it would be true
Explanation:
An ice cube melts on the warm sidewalk on a hot summer day. Let the entropies of the ice cube, of the pavement and of the ice cubesidewalk system be Sice, Ssw and Ssys. What happens to these entropies?
1. Sice increases, Ssw decreases, Ssys does not change.
2. Sice decreases, Ssw increases, Ssys decreases
3. Sice increases, Ssw decreases, Ssys increases
4. Sice increases, Ssw increases, Ssys increases
Answer:
3. Sice increases, Ssw decreases, Ssys increases
Explanation:
Entropy basically refers to the degree of disorderliness of a system.
Ice Cube --> As the ice cube melts, it undergoes a change in state of matter from solid to liquid hence it's entropy increases as the degree of movement of its molecules is more disordered in the liquid state.
This means the likely options are; 1, 3 and 4.
Sidewalk --> The entropy here decreases as the ice melts on the side walk. This is because there is a reduction in temperature. Entropy is directly proportional to temperature. Decrease in temperature leads to decrease in entropy.
This means the likely option is 1 and 3
The net entropy change of the system is however positive.
Which is an example of a compound? * He3 or H2O or C
Answer:
H2O
Explanation:
There is more than one element
Can someone answer 4 for me please?
If the gold in the crown was mixed with a less-valuable metal like bronze or copper, how would that affect its density?
Answer: If the gold in the crown was mixed with a less-valuable metal such as bronze of copper then this affects its density by making it to weigh even more and if it weighs more then it has less of chance to float. Observe: Drag each of the crowns into the liquid.
Explanation:
Density can be defined as the compactness of any substance. It is the mass/volume of a substance.
The density of gold is 19.3 g/ccThe density of copper is 9 g/ccThe density for bronze is 8.73 g/cc.Thus, if the gold crown is mixed with cheaper substances, such as bronze and copper, the density of the crown will decrease and it will become lighter.
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Determine the bond orders, relative stabilities, and magnetic properties of the peroxide ion, and the superoxide ion.
Answer:
See explanation
Explanation:
The molecular orbital configuration of the super oxide ion is;
σ1s2, σ*1s2, σ2s2, σ*2s2, σ2px2, π2py2, π2pz2, π*2py2, π*2pz1
The molecular orbital configuration of the peroxide ion is;
σ1s2, σ*1s2, σ2s2, σ*2s2, σ2px2, π2py2, π2pz2, π*2py2, π*2pz2
Hence the bond order of the superoxide ion is 1.5 while the bond order of the peroxide ion is 1.
The superoxide ion is paramagnetic while the peroxide ion is diamagnetic.
Since the superoxide ion has a greater bond order and will have resonance structures as a result of its fractional bond order, it is more stable than the peroxide ion.
A student in chemistry class mixes two clear solutions together. Which of the following is the best evidence that a chemical reaction has occurred?
Question 5 options:
The solutions are soluble when mixed together.
The volume of the liquids increased.
A Yellow precipitate is formed when mixed together.
One liquid is insoluble in the other liquid.
Answer:
a yellow precipitate is formed when mixed together
A student in chemistry class mixes two clear solutions together. Then, a Yellow precipitate is formed when mixed together.
What is the solution ?A particular kind of homogenous combination made up of two or more components is known as a solution. A solute is a material that has been dissolved in a solvent, which is the other substance in the combination.
In a combination called a solution, every component is well combined. Solutions can contain solids, liquids, and gases and are regarded as homogenous mixes. A solute plus a solvent makeup a solution. Any material that dissolves in a solvent is referred to as a solute.
Solid, liquid, and gaseous solutions can be classified as solutions based on the physical states of the solvent and solute. Both the solute and the solvent are in the solid state in solid solutions.
Thus, option C is correct.
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In atomic solids where the lattice points are occupied by Group 8 ( 18) atoms, the atoms are held together by __________ forces.
Answer:
London dispersion forces
Explanation:
There are different forces of attraction that helps to hold atoms or Molecules of a particular substance together. Some of the forces of attraction are ionic/ electrovalent bond, covalent bond, vander waals forces of attraction and so on.
Under the vander waals forces of attraction we have what is known as the London dispersion forces. This force of attraction is a very weak and it is commonly found in the atoms of noble gases.
The intermolecular force of attraction in which we are talking about that is london dispersion forces is formed as a result of the formation of non-polar dipoles which are not permanent.
How many atoms are in 2.37 moles of Krypton
Answer:
1.43 × 10²⁴ atoms Kr
General Formulas and Concepts:
Chemistry - Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
2.37 mol Kr
Step 2: Convert
[tex]2.37 \ mol \ Kr(\frac{6.022 \cdot 10^{23} \ atoms \ Kr}{1 \ mol \ Kr} )[/tex] = 1.42721 × 10²⁴ atoms Kr
Step 3: Check
We are given 3 sig figs. Follow sig fig rules and round.
1.42721 × 10²⁴ atoms Kr ≈ 1.43 × 10²⁴ atoms Kr
Which total mass is the largest?
(A) The mass of 2 electrons
(B) The mass of 2 neutrons
(C) The mass of 1 electron plus the mass of 1 proton
(D) The mass of 1 neutron plus the mass of 1 electron
Answer: B
Explanation: because the subatomic particle with the largest mass is the neutron.
Suppose an astronaut floating in space throws a rock. What will happen to the rock?
The density of aluminum is 2.7 g/cm3 and that of Al2O3 is about 4 g/cm3. Calculate the PB ratio for Aluminum. (Hint: The Pilling-Bedworth Ratio (PBR) gives the volume of oxide formed to the volume of metal atoms.)
a) 1.28
b) 0.28
c) 0.75
Answer:
1.28
Explanation:
Al = aluminium
Density of Al = 2.7g/cm³
Density of Al2O3 = 4g/cm³
Molecular weight of Aluminum = 27g/mol
Molecular weight of Al2O3= 101.96 g/mol
Pilling bedworth ratio = Rob
= M(Al2O3) * density of Al / n* molecular weight of Al * density of Al2O3
= 101.96g/mol x 2.7g/cm³/2x 27g/mol x 4g/cm³
= 275.292/216
= 1.28
From the calculation above 1.38nis the PB ratio for aluminum
what form of energy causes an ice cube to melt
A.mechanial
B.magnetic
C.sound
B.thermal
Answer:
Thermal
Explanation:
When something heats up its atoms become further apart making it melt when something heats up or gets heat or loses heat that's thermal energy
which two changes of state can be caused by removing thermal energy from a substace A. deposition B. condencation C. vaporization D.sublimation
Answer:
maybe is b but wait to other people answer
Answer:A. deposition B. condencation
Explanation:
how many molecules of nitrogen are in 1.25 mol N2?
Answer:
7.52 x 10²³ molecules N
Explanation:
multiply 1.25 mol of N2 by Avogadro's Number
What is the net ionic equation for the acid-base reaction between chlorous acid and sodium hydroxide?
Answer: [tex]HCO_2(aq)+OH^-(aq)\rightarrow ClO_2^-(aq)+H_2O(l)[/tex]
Explanation:
Neutralization is a chemical reaction in which an acid and a base reacts to form salt and water.
Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.
The reaction of chlorous acid (weak acid) and sodium hydroxide (strong base) is written as:
[tex]HClO_2(aq)+NaOH(aq)\rightarrow NaClO_2(aq)+H_2O(l)[/tex]
The equation can be written in terms of ions as:
[tex]HClO_2(aq)+Na^+(aq)+OH^-(aq)\rightarrow Na^+(aq)+ClO_2^-(aq)+H_2O(l)[/tex]
The ions which are present on both the sides of the equation are sodium ions and hence are not involved in net ionic equation.
Hence, the net ionic equation is :
[tex]HCO_2(aq)+OH^-(aq)\rightarrow ClO_2^-(aq)+H_2O(l)[/tex]
Balanced or Unbalanced
K+2MgBr=KBr+Mg
PLEASE HURRY!!! I WILL GIVE BRAINLEIST!!!!
Study the diagram of a cell. Which structures are found in both plant and animal cells? W and X W and Z X and Y O Y and Z XN Y -W
Answer:
A I did the exam and I saw A sorry if it is wrong dont have the best of memory
A balloon contains a mixture of 2 gases, X and Y. If the pressure in the balloon is 1.50 atm and there are 3 moles of X and 7 moles of Y present, what is the partial pressure of each gas?
Answer:
Partial Pressure of X = 0.45 atm
Partial Pressure of Y = 1.05 atm
Explanation:
Mixture of gas = Gas X + Gas Y
Total number of moles = 3 + 7 = 10 moles
Total pressure = 1.50 atm
The relationship between partial pressure, total pressure and number of moles is given as;
Partial pressure of gas X / Total pressure = Number of moles of gas X / Total number of moles
Partial Pressure of gas X / 1.50 = 3 / 10
Partial Pressure of gas X = 1.5 * 3 / 10 = 0.45 atm
The total pressure of a mixture is a sum total of the individual pressures, hence;
Pressure of mixture = Partial Pressure of X + Partial pressure of Y
1.5 = 0.45 + Partial pressure of Y
Partial Pressure of Y = 1.5 - 0.45 = 1.05 atm
Question 3 of 25
What is another name for Group 14?
Answer:
4A
Explanation:
on the periodic table
Need help please? Thanks youu
Answer:
A
B
E
Explanation:
"Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei
and fusion is the process where two light nuclei combine together releasing vast amounts of energy"
a process that releases energy is respiration
Please help!! On a timer!! If you can help me with any of the following questions please, I'm lost.
1. What is the density of a block of marble that occupies 251 cm^3 and has a mass of 933 g? Answer in units of g/cm^3
2. Lee pushes horizontally with a force of 45 N on an 18 kg mass for 12 across the floor. Calculate the amount of Lee did. Answer in units of J.
3. What is the mass number of an element with atomic number 10 and 10 neutrons.
Answer:
3. Answer= Neon (Ne) is the Group 8A chemical element that has atomic number 10 and mass 20.1797.
What energy allows for the difference in the spacing of molecules in a liquid versus a gas?
A. Electrical energy
B. Radiant energy
C. Potential energy
D. Kinetic energy
Answer:
kinetic energy
Explanation:
yeah it's correct
What is the frequency of visible light which has a wavelength of 625nm?
Answer:
The answer is 4.80 x 1014s-1b
Explanation:
625 nm x 10-9m= 6.25 x 10-7 m = c = 2.998 x 108m/s1 nm 6.25 x 10-7m=4.80 x 1014s-1b.)
The frequency of visible light is equal to 4.8 ×10¹⁴s⁻¹.
What are frequency and wavelength?Frequency can be described as the number of oscillations of a wave in a time of one second. The frequency of the wave or light has S.I. units which are per second (s⁻¹) or hertz.
Wavelength can be defined as the distance between the two adjacent points of a wave in the phase with each other. Two adjacent crests or adjacents troughs on a wave are separated by a distance is called wavelength.
The relationship between the speed of light, frequency, and wavelength is:
c = νλ
Given, the wavelength of the light, λ = 625nm = 625 × 10⁻⁹ m
Then we know that the speed of light, c = 3 × 10⁸ ms⁻¹
The frequency of the light can be calculated from the above-mentioned equation:
The frequency of the given visible light will be equal to:
ν = c/λ = 3× 10⁸ ms⁻¹/625 × 10⁻⁹ m = 4.8 ×10¹⁴ Hz
Therefore, the frequency of visible light is equal to 4.8 ×10¹⁴ Hz.
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Select the correct definition below for the vocabulary term Oxygen
Answer:
Explanation:
We should be offered choices since you were offered some. However I will take a chance on what you should answer.
Oxygen is a non metal. Its most common charge is -2 which means that it has taken on two electrons. It is associated with fire and is an oxidizing agent which is a substance that will take on electrons). It is very reactive.
Most elements are __ at room temperature
Answer:
Most elements are Solids at room temperature
[40 points] How do I find the average atomic masses of these?
Answer:
14.02 amu
Explanation:
The following data were obtained from the question:
Isotope A (N–13):
Mass of A = 13 amu
Abundance (A%) = 28.97%
Isotope B (N–14):
Mass of B = 14 amu
Abundance (B%) = 41.04%
Isotope C (N–15):
Mass of C = 15 amu
Abundance (C%) = 29.97%
Average atomic mass of nitrogen =?
The average atomic mass of nitrogen can be obtained as illustrated below:
Average = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(13 × 28.97)/100] + [(14 × 41.04)/100] + [(15 × 29.97)/100]
= 3.77 + 5.75 + 4.50
= 14.02 amu
Thus, the average atomic mass of nitrogen is 14.02 amu
