Answer:
true
Explanation:
Answer:
True, new evidence can lead to a change in scientific knowledge.
Explanation:
Mosquitoes lays eggs that must hatch in water. The young, called larvae live their first few days in water
Which sentence best describes where you will most likely find mosquitoes and their eggs during the dry season in the Florida Everglades?
A.They will be spread out because water is everywhere.
B.They will be mainly in one area because water is everywhere
C. They will be in fewer areas because water is scarce
D. They will be everywhere because water is scarce.
Answer:
Explanation:
I believe he is C
NEED ASAP WILL MARK BRAINLIEST ON TIMER
A student determines that she used 0.0665 mol of sodium hydroxide (NaOH) to completely titrate 25.00 mL of sulfuric acid solution (H2SO4). What is the molarity of the sulfuric acid?
0.00131 M
0.00262 M
1.31 M
2.62 M
A student determines that she used 0.0665 mole of sodium hydroxide (NaOH) to completely titrate 25.00 mL of sulfuric acid solution. The molarity of the sulfuric acid is 1.31 M. Therefore, option C is correct.
What is molarity?Number of moles of solute per liter of solution is known as molarity.
The balanced chemical equation for the reaction between sodium hydroxide and sulfuric acid is:
2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O
According to the balanced equation, one mole of sulfuric acid reacts with two moles of sodium hydroxide. Therefore, the number of moles of sulfuric acid in the titrated solution can be calculated as:
moles of H₂SO₄ = (moles of NaOH) / 2
moles of H₂SO₄ = 0.0665 mol / 2
moles of H₂SO₄ = 0.03325 mol
The volume of the sulfuric acid solution used in the titration is 25.00 mL, which is equivalent to 0.02500 L. The molarity (M) of the sulfuric acid can be calculated as:
Molarity of H₂SO₄ = moles of H₂SO₄ / volume of H₂SO₄ solution in liters
= 0.03325 mole / 0.02500 L
= 1.31 M
Thus, option C is correct.
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As the kinetic energy of particles of matter increase, the distance between the particles?
Which of the following best summarizes photosynthesis?
A.A chemical reaction involving nitrogen and other atmospheric gases
B.An adaptation of plants that allows them to add nutrients to the soil
C.A process by which plants produce sugar using the energy of sunlight
D.An exchange of gases between animals and the air or water of their habitat
Answer:
c. a process by which plants produce sugar using energy of sunlight
1-Which reaction shown below is carried out by nitrifying bacteria? I will mark you as brainlist
Choose:
A.{ammonium} to {nitrate}
B.{nitrate} to {nitrogen gas}
C.{nitrogen gas} to{ammonium}
Answer:
ammonium to nitrate.
Explanation:
they tie em together
EMERGENCY: I WILL FAIL: PLS HELP WILL MARK BRAINLIEST JUST PLS HELP
Answer:
condensation: moisture builds up on window; dew forms on blades of grass
deposition: snow is made inside a cloud; frst froms on window?
Explanation:
How many grams of NaCl are needed to prepare 1.20 liters of a 2.00 M solution?
Answer:
140 grams NaCl is needed
Explanation:
i used this How many grams of NaCl in 50 mL of 0.75 M NaCl solution? The MOLARITY of a solution is determined by the ratio of moles of solute, (the material being dissolved), compared to the liters of solution. the equation is M = mol L For this NaCl solution we have a Molarity of 0.75 in 50 mL of solution. Then i multiplied it by the correct amount
If a buffer has an initial pH of 6.34 and the acid has a Ka of 3.46 × 10-4, what is the ratio of conjugate base to weak acid in the buffer system?
Answer: The ratio of conjugate base to weak acid in the buffer system is 758 : 1
Explanation:
The dissociation constant for acid = [tex]K_a=3.46\times 10^{-4}[/tex]
pH = 6.34
First we have to calculate the value of [tex]pK_a[/tex].
The expression used for the calculation of [tex]pK_a[/tex] is,
[tex]pK_a=-\log (K_a)[/tex]
Now put the value of [tex]K_a[/tex] in this expression, we get:
[tex]pK_a=-\log (3.46\times 10^{-4})[/tex]
[tex]pK_a=3.46[/tex]
Now we have to calculate the ratio of conjugate base to weak acid in the buffer system
Using Henderson Hesselbach equation :
[tex]pH=pK_a+\log \frac{[\text {conjugate base}]}{[Acid]}[/tex]
Now put all the given values in this expression, we get:
[tex]6.34=3.46+\log \frac{[\text {conjugate base}]}{[Acid]}[/tex]
[tex]\frac{[\text {conjugate base}]}{[Acid]}=758[/tex]
Therefore, the ratio of conjugate base to weak acid in the buffer system is 758: 1
Answer:
A. 1:0.46
Explanation:
I took the test
An insulator,
Keeps electrons inside the nucleus of an atom
Allow electrons to move easily through an object
Is when electrons cannot move through objects easily
a put question in screen shot
Answer:maybe 2
Explanation:
Answer:
2
Explanation:
Which planet do scientists believe prevented the asteroids in the asteroid belt from forming a planet? Earth Jupiter Mars Neptune
Answer:
Jupiter
Explanation:
Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, thats why asteroids collide today.
sorry if its wrong .
Answer:
Your answer is Jupiter
Explanation:
I TOOK THE TEST AND I LEARNED THIS
Static electricity is
a closed conducting path
when electrons move easily through objects
build up of electrical charges by friction
Describe the interactions with the Sun, Earth and Moon system that result in Lunar Cycle / Phases.
Answer: The tides are another interaction in the sun-earth-moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day. The moon has a bigger effect than the sun because it is closer. The angle of the sun as the earth orbits over the course of a year causes the seasons.
Explanation:
A gas has a volume of 3.00 L at 65.0 C. The same gas has a volume of 11.4 L at 105 C and 1725 mmHg. What was the original pressure of the gas?
What are two scientific fields that utilize facial reconstruction?
Answer:
The facial reconstruction problem arises in various application fields like forensics, anthropology, archeology or history. In forensic science, facial reconstruction comes in the process of identification of deceased people
Explanation:
How many grams of ammonia (NH3) are present in 5.0L of a 0.050M Solution?
A. 5.2g
B. 4.3g
C. 4.3mol
D. 78g
Answer:
B
Explanation:
NH3 in a liter is 17 x 0.05 = 0.85g
In 5L = 0.85 x 5 = 4.25 = 4.3g
Answer:
B. 4.3 g
Explanation:
m = 5.0L x 0.050 mol/L x 17.031 g/mol = 4.26g ~ 4.3g
....
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
What reactants would you use to produce Mg(No3)2 and H2
Explanation:
This is a single replacement reaction, so we just have to switch Mg and H₂. When we do so, we get HNO₃ and Mg as our reactants. Hope this helps!
1. What are the trends for atomic size across a period and down a group for the
main group elements?
2. Draw the following Lewis structures:
a) ammonium ion b) sulfur trioxide c) hydrogen cyanide
3. Using formal charge formula (or electronegativity differences), to determine
the following the best structure, OCS, COS or CSO.
Answer:
Here's what I get
Explanation:
1. Trends in atomic size
Atomic size tends to decrease from left to right across the Periodic Table.
You are adding one electron at a time. the electrons repel each other, so the size should increase.
You are also adding a proton to the nucleus. The additional attraction should pull the electrons closer to the nucleus.
The nuclear pull wins, so the atoms get smaller from left to right
Atomic size increases from top to bottom of a Group.
You are adding electrons to an extra shell, so the size should increase.
You are also adding protons to the nucleus, so the size should decrease.
The size of the outer shell wins, so the atomic size increases going down a Group.
2. Lewis structures
(a) Ammonium ion
N is the central atom. The N atom has the positive charge.
(b) Sulfur trioxide
S is the central atom, with a double bond to each of the three O atoms.
(c) Hydrogen cyanide
C is the central atom, with a triple bond to the N atom.
3. COS
The best structure is that of O=C=S. It has no formal charges.
The Lewis structures for the other arrangements have formal charges.
The correct answers of this question is given below.
1. The atomic size increases going down a Group.2. (a) Ammonium ion : The N atom has the positive charge. (b) Sulfur trioxide : Having double bond to each of the three O atoms. (c) hydrogen cyanide : Having a triple bond to the N atom.3. COS and it has no formal charges What is Periodic table?A table in which the chemical elements are arranged in order of increasing atomic number.A periodic table has 118 known elements The chemical elements are arranged from left to right and top to bottom in order of increasing atomic number.What is the explanation for this answers?1. Trends in atomic size : Atomic size tends to decrease from left to right across the Periodic Table.You are adding one electron at a time. the electrons repel each other, so the size should increase.You are also adding a proton to the nucleus. The additional attraction should pull the electrons closer to the nucleus.The nuclear pull wins, so the atoms get smaller from left to right.Atomic size increases from top to bottom of a Group.Adding electrons to an extra shell, so the size should increaseAdding protons to the nucleus, so the size should decrease.The size of the outer shell wins, so the atomic size increases going down a Group.2. Lewis structures :
(a) Ammonium ion : N is the central atom. The N atom has the positive charge. (b) Sulfur trioxides : S is the central atom, with a double bond to each of the three O atoms.(c) Hydrogen cyanide: C is the central atom, with a triple bond to the N atom3. COS
The best structure is that of O=C=S. It has no formal charges.The Lewis structures for the other arrangements have formal charges.Learn more about atomic size below,
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what is the compound of p2o5
Answer:
Phosphorus pentoxide is a chemical compound with molecular formula P4O5 (with its common name derived from its empirical formula, P4O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful dessicant and dehydrating agent.
Explanation:
it would be phosphoric acid.
According to plate tectonics, the continents.
do not move at all
are drifting on a sea of magma
will one day be joined together
"float' on top of the crust
Answer:
are drifting on a sea of magma.
Explanation: Please mark brainliest.
What does a dissolved salt look like?
A. The salt crystals are surrounded by water molecules.
B. The salt crystals separate into salt molecules in the water.
C. The salt separates into ions that settle to the bottom
D. The ions in the salt are surrounded by water molecules.
Answer:
I want to say your answer is B)
The answer is D because the ions in the salt will be surrounded by water molecules
Dissolution in water occurs as a result of ionic interactions. This means that the ions (charged atoms) of the solute has to interact with the ions of water for the solute to dissolve. Based on this principle, only polar compounds can dissolve in water.
According to this question, salt is polar because it contains positive (+) and negative (-) ions. Hence, when placed in water, these ions will interact with the ions of water i.e. H+ and OH-. This causes dissolution of salt in water to form salt solution.
Hence, a dissolved salt will look like "ions in the salt are surrounded by water molecules".
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Identity the anode and cathode
Answer:
Pb(s) ---> Pb+2 + 2e- is the anode
Cu+2(aq) + 2e- ---> Cu(s) is the cathode
I need the correct answer
Answer:
d.
Explanation:
They can be spread through contaminated surfaces.
Answer:
d
Explanation: pathogens csnnot be spread be sontaminated surfesec
Is amylopectin a straight chain polysaccharide
Answer:
hey friend, Amylopectin is a branched chain.
what two factors does elastic potential energy depend upon
Answer: Spring constant k as well as the distance stretched
Explanation:
Elastic potential energy is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched.
A(n)
image cannot be projected and forms where light rays appear to originate.
Answer:
Eu não sei o que você está dizendo, mas boa sorte
Answer: Virtual
Explanation: A virtual image is an image that can not be formed on a screen. This type of an image is formed when the rays of light appear to meet at a point after reflection or refraction. Virtual images are always erect or upright.
Which formula represents an alkane?
1.
C2H2
2.
C2H4
3.
C3H4
4.
С3Н8
Answer: Option 4) is correct.
Explanation: It is correct because alkanes have a general formula CnH2n+2. So, all we need to do is substitute and find out how many hydrogens are needed to make the formula an alkane. I am not really good at explaining. I am sorry If I confused you.
Alkanes are the organic compound which has general formula [tex]C_{n}H_{2n +2}[/tex] which satisfies the formula [tex]C_{3}H_{8}[/tex]. Hence [tex]C_{3}H_{8}[/tex] represents an alkane.
AlkaneAlkanes are simplest saturated hydrocarbon. Alkanes are also known as paraffins wax. Alkanes which contains only carbon and hydrogen atoms.
General Formula of AlkaneThe general formula of alkane is [tex]C_{n} H_{2n + 2}[/tex] where n = 1, 2, 3, 4.......
Consider Option 1, [tex]C_{2}H_{2}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2}[/tex] = [tex]C_{2} H_{4 + 2}[/tex] = [tex]C_{2} H_{6}[/tex] , so option 1 does not satisfies the above formula. Hence it is incorrect. Consider Option 2, [tex]C_{2} H_{4}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2} = C_{2} H_{4 + 2} = C_{2} H_{6}[/tex], so option 2 does not satisfies the above formula. Hence it is incorrect. Consider Option 3, [tex]C_{3} H_{4}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 3 does not satisfies the above formula. Hence it is incorrect. Consider Option 4, [tex]C_{3} H_{8}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 4 satisfies the above formula. Hence it is correct.Thus, from the above conclusion we can see that option 4 [tex]C_{3}H_{8}[/tex] represents an alkane.
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CAN SOMEONE HELP ME?!?! IM CONFUSED
Answer: Solar winds have an influence all the way to about 160 AU from the Sun. About how many kilometers is that?
24,000,000,000 km
48,000,000,000 km
240,000,000,000 km
480,000,000,000 km
Explanation:
If the acetylene tank contains 37.0 mil of C2H2 and the oxygen tank contains 81.0 mol of O2, what is the limiting reactant for this reaction
2C2H2(l)+502(g) 4CO2(g)+2H2O(g)
Answer:
Explanation:
2C₂H₂(l) + 50₂(g) = 4CO₂(g) + 2H₂O(g)
2 mol 5 mol
2 mol of C₂H₂ reacts with 5 mol of O₂
37 mol of C₂H₂ will require 5/2 x 37 mol of O₂
= 92.5 mol of O₂
But oxygen available is only 81 mol so formation of product will be controlled by oxygen available . Hence oxygen is the limiting factor.
I need simple answers that a 14-year-old would understand.
What are valence electrons?
What is the difference between the Rutherford and Thompson plum pudding model?
What relative scale for atoms do chemists use? Why do they use this?
Compare and contrast alpha, beta and gamma decay of radionuclides.
Explain why radiation is dangerous for living cells but can be applied to treat people with some forms of cancer.
Explain why oxygen atoms ionise to form the oxide ion with a charge of –2. Identify if oxide is an anion or a cation.
Answer:
1. The Nummber of electrons present in the outermost shell is called Valence electrons.
2. Thomson model:
Thomson model of atom is the model which states that electrons are embedded in a positively charged solid material which is spherical in shape.
Rutherford model
Rutherford model of atom is the model which explains that there is a nucleus in the center of the atom and electrons are located around the nucleus.
3. Relative atomic mass. Atoms have very little mass , so they're difficult to measure accurately. Instead, chemists use a scale. On this scale the mass of a 12C atom is exactly 12.
4. Difference between Alpha, Beta and Gamma radioactive decay:
Alpha decay forms new element with two fewer protons and two fewer neutrons;
Beta decay forms new element with one more proton and one fewer neutron.
Gamma decay forms NO new element, but now the element has less energy because energy is released as gamma rays.
Gamma radiation has the highest penetration power, Beta decay goes the second, alpha decay the last. However, alpha particles make the most damage even if it has the lowest penetration power among the three.
5. This species has a 2− charge on it, so it is an anion. Anions are named using the stem of the element name with the suffix -ide added. This is the oxide anion.
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