Answer:
3) organism organ system organ tissue cell
Explanation:
What is the mass number of an atom that has 19 protons, 19 electrons, and 20 neutrons?
Answer:
[tex]\boxed {\boxed {\sf 39}}[/tex]
Explanation:
The mass number of an atom can be found by adding the number of protons and neutrons.
[tex]mass \ number =protons + neutrons[/tex]
There are 19 protons and 20 neutrons.
[tex]protons=19 \\neutrons=20[/tex]
[tex]mass \ number= 19+20[/tex]
[tex]mass \ number =39[/tex]
The mass number of this atom is 39
A chemistry student conducted several different procedures. Which of the following procedures best demonstrates the law of conservation of mass?
O using filter paper to separate 2 grams of solid powder from 10 grams of water
O burning 2 kilograms of wood from a pine tree leaves 0.4 kilogram of ash and soot
O evaporating sugar water leaves 5 grams of sugar and turns the water into water vapor
O combining 2 grams of copper and 4 grams of sulfur to make 6 grams of copper sulfate
Answer:
combining 2 grams of copper and 4 grams of sulfur to make 6 grams of copper sulfate
Explanation:
The Law of Conservation of Mass states that matter cannot be created or destroyed in chemical reactions. It posits that the mass of a substance remains unchanged after undergoing a chemical process.
Therefore, according to the question, the procedure that best demonstrates the law of conservation of mass after the chemistry student conducted different procedures is option D.
This is because, the mass of copper and sulfate did not change but merely combined to form a compound.
a sample gas is in the rigid cylinder with a movable piston the pressure of the gas is kept constant if the kelvin temperature of the gas is doubled the volume of the gas is?
Answer:
The pressure of the gas is kept constant. If the Kelvin temperature of the gas is doubled, the volume of the gas is. O 1.
A compound of copper and sulfur contains 76.84 g of metal and 38.53 g of nonmetal. How many grams of copper are in 3801 kg of the compound? How many grams of sulfur?
Answer:
There are:
2'531,500 g Cu1'269,500 g SExplanation:
First calculate the percentage of Cu and S in the compound:
Total mass = 76.84 g + 38.53 g = 115.37 g% metal (Cu) = 76.84/115.37 * 100% = 66.6%% metal (S) = 38.53/115.37 * 100% = 33.4%These percentages will remain the same no matter how much of the compound we analyze.
Now we calculate the grams of Cu and S in 3801 kg of the compound:
kg Cu = 3801 kg * 66.6/100 = 2531.5 kg Cug Cu = 2531.5 kg * 1000 = 2531500 g Cukg S = 3801 kg * 33.4/100 = 1269.5 kg Sg S = 1269.5 kg * 1000 = 1269500 g SWhy does determining volume work only for a regular shaped object
Answer:
Because only regular-shaped objects have a consistent length, width, height, and shape.
Explanation:
Because only regular-shaped objects have a consistent length, width, height, and shape. When dealing with an object composed of differing shapes, your must calculate each portion separately and then add them.
What energy is required for a reaction to occur?
A. Bond energy
B. Activation energy
C. Kinetic energy
D. Potential energy
Answer:
B. Activation Energy
Explanation: A P E X
Answer: the answer is activation energy
Explanation:
i just took the test
2.If a liquid has a volume of 5800 mL and you need the volume in Liters, will the number appear to
become smaller or larger?
Answer:
The number becomes smaller
Explanation:
Volume = 5800mL
To be converted to L
The relationship between mL and Liters is given as;
1 L = 1000 mL
This means that;
1 L = 1000 mL
x L = 5800 mL
x = 5800 / 1000 = 5.8 L
Comparing 5.8 with 5800, the number becomes smaller.
A solution containing HCI would likely have
a high pH and a low pOH.
a low pH and a high pH.
a high pH and a high poH.
a low pH and a low poH
Answer:
B on EDGE 2021
Explanation:
THE ANSWER ABOVE IS INCORRECT brainliest pls?
Given the solution containing HCl, the solution is likely to have a low pH and a high poH
What is pH ?This is simply a measure of the acidity / alkalinity of a solution.
The pH measures the hydrogen ion concentration while the pOH measures the hydroxide ion concentration
pH scaleThe pH scale is a scale that gives an understanding of the variation of the acidity / alkalinity of a solution.
The scale ranges from 0 to 14 indicating:
0 to 6 indicates acid 7 indicates neutral 8 to 14 indicate basicHowever, it should be noted that as the pH increases, pOH decreases and as pH decreases, pOH increases.
Considering the question given above, the solution (HCl) is acidic.
Therefore, the solution will have a low pH and a high pOH
Learn more about pH:
https://brainly.com/question/3709867
A scientist performs an experiment involving the collision of two masses on a flat surface. She believes she has made a startling discovery: the total kinetic energy is not conserved. What might she have overlooked?
A.
Some gravitational potential energy may have been gained.
B.
Some gravitational potential energy may have been lost.
C.
Some energy may have been gained due to friction and/or sound.
D.
Some energy may have been lost due to friction and/or sound.
Answer:
c
Explanation:
What is the answer? Please
2. A person with a body temperature of 37°C holds an ice cube with a temperature of 0°C
in a room where the air temperature is 20°C. The direction of heat flow is
a) From the person to the ice, only
b) From the person to the ice and air, and from the air to the ice
c) From the ice to the person, only
d) From the ice to the person and air, and from the air to the person
Answer:
b) From the person to the ice, and from the air to the ice
Explanation:
The direction of heat flow in the room is from the person to the ice and from the air to the ice.
The ice is at the lowest temperature.
Heat flows from a place with a higher measure of heat to a place with a lower amount of heat. Since the ice has the lowest heat, there is a thermal gradient set up. Heat will flow from the body and air towards to the ice.defferent between crysttiline solid and amerphus solid
Answer:
Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points. In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.
Explanation:
Hope this helped!
Answer:
Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points. In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.
Explanation:
What does this passage explain about people?
why mothers favor some children over others
the contrasting sides of human nature
why there is harmony in all things
left- and right-handedness
Answer:
the contrasting sides of human nature
Explanation:
I took the test
10. For each of the following pairs of ionic compounds, state which would be expected to have the higher (more negative) lattice energy.
a. LiF or KBr
b. NaCl or MgS
c. MgO or RbI
Answer:
C I belive
Explanation:
The higher lattice energy in option a is for LiF. Similarly, MgS have higher lattice energy that NaCl and MgO have higher lattice energy than RbI.
What is lattice energy?Lattice energy of a compound is the energy required to convert one mole of that compound into its constituent gaseous ions. Lattice energy increases as the size of the ion decreases. As well as, higher the charge of the ions higher will be the lattice energy.
In LiF and KBr, Li and F are the smaller ions and is having higher lattice energy. In the case of NaCl and MgS, Mg and S are having +2 charge and are smaller causes MgO higher in lattice energy.
Similarly in the case of MgO and RbI the same concept can be applied. Rb⁺ and I⁻ are bigger ions where as Mg²⁺ and O²⁻ are comparatively smaller and have higher charge result in higher lattice energy.
Thus compound which have higher lattice energy in option a is LiF, in option b is MgS and in option C is MgO.
To learn more about lattice energy, refer the link below:
https://brainly.com/question/17011733
#SPJ2
What happened to solid materials when mixed with the liquid materials?
Answer:
the solid materials will disappear after mixing with a liquid material
plsss mark me as brainliest answer plsssssssss
Answer: go fk your dad you fkin whor
3. Find
out the initial energy level (n) of an electron that results in the emi ssion of light of
wavelength 486 nm in the Balmer series?
Answer:
4
Explanation:
The Balmer series refers to a series of spectral emission lines of the hydrogen atom arising from electronic transitions from any higher level and terminating at the the energy level n= 2.
Using the relation;
1/λ = 1.09737*10^7 (1/2^2 -1/n^2initial)
We now have;
1/486 *10^-9 = 1.09737*10^7 (1/2^2 -1/n^2initial)
0.1875 = 1/2^2 -1/n^2initial
1/n^2initial = 1/2^2 - 0.1875
1/n^2initial = 0.0625
n^2initial = 16
ninitial = 4
Can you answer these two questions right please and thank you
Answer:
B. LZAQD
A. Younger than A but older than Q
Explanation:
To solve this problem, we simply apply the stratigraphic laws which are the law of superposition and principle of cross cutting.
According to the law of superposition, in an undeformed sequence of strata, the oldest layer is always at the bottom and the youngest on top. In this case, we have a little disturbance but it did not affect much of the original bedding. So, the rock ages from L to Z to A to Q and D. L is the oldest and D is the youngest.According to the principle of cross-cutting "features that cuts through a rock are younger than the layers they cut through". In this problem, the fault cuts through layers LZ and A which suggests that these layers are older than the faulting event. Layer Q is unaffected by the faulting so, the fault is older than the layer.
Toluene is subjected to the action of the following reagents in the order given: (1) KMnO4,OH-, heat; then H3O (2) HNO3, H2SO4 (3) Br2, FeBr3 What is the final product of this sequence?
Answer:
See image attached
Explanation:
The reaction of toluene with alkaline potassium permanganate in the presence of heat leads to the oxidation of the -CH3 to give benzoic acid.
Reaction benzoic acid with HNO3/H2SO4 yields the nitronium ion (NO2+).
Recall that -COOH is a metal director and deactivated the ring towards electrophilic substitution hence the m-nitrobenzoic acid is formed.
Reaction with FeBr3/Br2 yields the product shown in the image attached.
1 What is the total number of valence electrons in the Lewis structure of C104?
electrons
2 Draw a Lewis structure for CI04:
A competitive high school swimmer takes 56.7 seconds to swim 100. yards. What is his rate in m/min?
m
min
Answer:
96.72 m/min
Explanation:
The following data were obtained from the question:
Time (t) = 56.7 s
Distance (d) = 100 yard
Rate (R) =?
Next, we shall convert 56.7 s to minutes. This can be obtained as follow:
60 s = 1 min
Therefore,
56.7 s = 56.7 s × 1 min /60 s
56.7 s = 0.945 min
Next, we shall convert 100 yard to metre (m). This can be obtained as follow:
1 yard = 0.914 m
Therefore,
100 yard = 100 yard × 0.914 m /1 yard
100 yard = 91.4 m
Finally, we shall determine the rate of the swimmer as follow:
Time (t) = 0.945 min
Distance (d) = 91.4 m
Rate (R) =?
R = d/t
R = 91.4/0.945
R = 96.72 m/min
Thus the rate of the swimmer is 96.72 m/min
22. Metallic compounds
a. are poor conductors of electricity
b. dissolve in water
c. have low melting points
d. can be hammered into sheets
I need help with this, please I need it ASAP
It's science, ignore that it says Chemistry. There was no science
Calculate how many grams of sodium hypochlorite can be theoretically formed when 1.23 mol of sodium hydroxide is combined with 1.36 mol of chlorine.
Answer:
45.78 g NaClO
Explanation:
The reaction that takes place is:
2NaOH + Cl₂ → NaCl + NaClO + H₂OIn order to react completely, 1.36 moles of chlorine would require (2*1.36) 2.72 moles of NaOH. There are more moles than that, so NaOH is the limiting reactant.
We calculate the moles of NaClO formed, from the limiting reactant:
1.23 mol NaOH * [tex]\frac{1molNaClO}{2molNaOH}[/tex] = 0.615 mol NaClOFinally we convert NaClO moles to grams, using its molecular weight:
0.615 mol NaClO * 74.44 g/mol = 45.78 g NaClOA collection of the same kind of cells working together to do the same job
Answer:
A group of cells doing the same job forms a tissue. A group of tissues working together forms an organ. Organs work in groups, too. A group of organs doing the same job is called a system.
Explanation:
A student has a balloon with a volume of 2.5 liters that contains 4.0 moles of air. The ballon has a small leak, allowing one mole to escape, leaving just 3.0 moles of air inside the balloon. What is the balloon's new volume after the air has escaped?
Answer:
1.9 L
Explanation:
Step 1: Given data
Initial number of moles of air (n₁): 4.0 molInitial volume of the balloon (V₁): 2.5 LFinal number of moles of air (n₂): 3.0 molFinal volume of the balloon (V₂): ?Step 2: Calculate the final volume of the balloon
According to Avogadro's law, the volume of an ideal gas is directly proportional to the number of moles. We can calculate the final volume of the balloon using the following expression.
V₁ / n₁ = V₂ / n₂
V₂ = V₁ × n₂ / n₁
V₂ = 2.5 L × 3.0 mol / 4.0 mol
V₂ = 1.9 L
20. What part of an atom exists in orbitals surrounding the nucleus?
A. electron
B. photon
C. neutron
D. proton
what is Acid and any type of acid
Answer:
Acid is the substance which gives H+ ions when dissolved in an aqueous solution and tastes sour.
Types of acid
Strong acidWeak acidAnswer:
An acid is a molecule or ion capable of donating a proton (hydrogen ion H+) or, alternatively, capable of forming a covalent bond with an electron pair.
Explanation:
Hope this helped!
Which statement is true of an endothermic reaction? a) Weak bonds break and strong bonds form. b) Strong bonds break and weak bonds form. c) The bonds that break and those that form are of approximately the same strength.
Answer:
B
Explanation:
In an endothermic reaction, strong bonds break and weak bonds form.
Assume a density of water of 1.00 g/mL, and calculate the mass of water in the solution
Answer:
1g or 10^-3kg
Explanation:
as you know , the density =mass \volume
so you have the mass from the number it self
[tex]\frac{1g}{1 ml}[/tex] so from this equation, you will get 1 g and you can to SI to be [tex]10^{-3}[/tex]kgWhich of the following shows the abbreviation for an SI unit of density?
the aswer is g/ml hope is helpful