Answer:
D
Explanation:
Independent variables (IV): These are the factors or conditions that you manipulate in an experiment. Your hypothesis is that this variable causes a direct effect on the dependent variable. Dependent variables (DV): These are the factor that you observe or measure.
Help me first to answer will get brainliest
What is an example of a reservoir?
(A )Beach (B )Cloud (C )Desert (D )Lake
Answer:
the answer should be Lake
Answer: D
Explanation:
Which statements about viruses are true? Select all that apply.
Viruses can be seen with a compound light microscope.
Viruses vary greatly in size and structure.
Some viruses contain RNA instead of DNA.
Some viruses use the cell's machinery to replicate more viruses.
Plant viruses can infect animals if ingested.
Bacteriophages are viruses that infect bacteria, plants, and animals.
Answer:
Viruses can be seen with a compound light microscope.
Viruses vary greatly in size and structure
Some viruses use the cell's machinery to replicate more viruses
Explanation:
please don't report me I just want to make you feel good I beg you
Answer:
this comic was pretty funny
In Chromium-53, the "53" represents the
Answer:
The differemt isotopes that differ in atomic mass
Explanation:
is the reaction balanced?
Answer:No there needs to be fewer red on the reactant side.
Explanation:
MULTIPLE CHOICE
A student added phenolphthalein to two solutions. Solution A remained clear while Solution B
turned pink. Which of the following could be the pH of Solution B?
The pH of the solution B will be 10.
• One of the indicators that helps the chemists to determine visually that whether the substance is an acid or a base is the phenolphthalein.
• The phenolphthalein changes color due to ionization, and this changes the shape of the molecules of phenolphthalein.
• Naturally, phenolphthalein is colorless, however, it turns pink in alkaline solutions.
• The solution turns pink at the pH ranging between 8.2-10.
• Phenolphthalein has two distinct compositions based on whether it is an acid (colorless) or alkali (pink) solution.
Thus, turning of solution B to pink color by adding phenolphthalein indicator shows that the pH of the solution would be 10 based on the given options.
To know more about:
https://brainly.com/question/16784630
Ethyl alcohol evaporates faster then water, why?
Answer:
because it melting point is low
Answer:
Alcohol evaporates because of its vapor pressure and therefore, its molecule lying at the surface of alcohol (liquid-gas boundary) breaks its hydrogen bonding and tends to escape out of the alcohol solution. It should be noted that alcohol evaporates at a faster rate than water.
Five molecules will enter the BODY of an organism(1.Amino Acids, 2. Protein, 3. Glucose, 4. Starch, and 5. Oxygen). However, only three molecules will actually enter the CELLS. Which three molecules will enter every cell in the human body?
Explain how the periodic table is organized. Include the following in your response: What is the relationship between elements in the same group? How does an element's location on the periodic table relate to its reactivity? Describe the properties of the following families of elements: Hydrogen, Alkali Metals, Alkaline Earth Metals, Halogens, and Noble Gases.
Answer:
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WRITTEN BY
J.J. Lagowski See All Contributors
Professor of Chemistry, University of Texas at Austin. Author of The Chemical Bond.
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Alternative Title: periodic table of the elements
Study chemistry's periodic law to understand elements' properties and how they relate to one another
Study chemistry's periodic law to understand elements' properties and how they relate to one another
Explanation of the periodic table.
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Periodic table, in full periodic table of the elements, in chemistry, the organized array of all the chemical elements in order of increasing atomic number—i.e., the total number of protons in the atomic nucleus. When the chemical elements are thus arranged, there is a recurring pattern called the “periodic law” in their properties, in which elements in the same column (group) have similar properties. The initial discovery, which was made by Dmitry I. Mendeleyev in the mid-19th century, has been of inestimable value in the development of chemistry.
periodic table
Explanation:
need thanks and make me brainiest if it helps you
true of false? After Vincennes was recaptured by the British,
George Rogers Clark captured it again in a
surprise attack.
if it’s false give an explanation why
Answer:
False
Explanation:
Answer:Terms in this set (17)
T/F Mohawk war chief Joseph Brant was one of the few Native Americans who sided with the Patriots. ... After George Rogers Clark captured Vincennes, it remained in Patriot control. True. After Vincennes was recaptured by the British, George Rogers Clark captured it again in a surprise attack.
Explanation:
Which pair of elements form in a conic bond with each other
I think you mean ionic bond and not conic bond. The pair of elements that form an ionic bond are barium and chlorine.
Can someone please walk me through this?-- 25 pts!
Calculate the change of enthalpy for the reaction CH4 (g) + NH3 (g) --> HCN (g) +3H2 (g) from the following reactions:
Reaction 1: N2 (g) + 3H2 (g) --> 2NH3 (g); Change in enthalpy: -91.8 kJ/mol
Reaction 2: C (s, graphite) + 2H2 (g) --> CH4 (g); Change in enthalply: -74.9 kJ/mol
Reaction 3: H2 (g) + 2C (s, graphite) + N2 (g) --> 2HCN (g); Change in enthalpy: +270.3 kJ/mol
I have to include the following:
The numerical answer with correct units.
State which reactions, if any, you had to "Flip".
State which reactions you had to multiply, if any, to get the correct amount of the compound. Also, include how much you multiplied the reaction by.
NH3(g) + CH4(g) ⇒ HCN + 3H2 ∆ H:255.95 kJ/mol
Further explanationGiven
Reaction and the enthalpy
Required
The change of enthalpy
Solution
Reaction 1
N2 (g) + 3H2 (g) --> 2NH3 ∆ H: -91.8 kJ/mol⇒reverse
2NH3 ⇒ N2 (g) + 3H2 (g) ∆ H: +91.8 kJ/mol
Reaction 2
C (s, graphite) + 2H2 (g)⇒ CH4 (g) ∆H: -74.9 kJ/mol ⇒reverse
CH4 (g) ⇒ C (s, graphite) + 2H2 (g) ∆H: +74.9 kJ/mol ⇒ x2
2CH4 (g) ⇒ 2C (s, graphite) + 4H2 (g) ∆H: +149.8 kJ/mo
Reaction 3
H2 (g) + 2C (s, graphite) + N2 (g) ⇒ 2HCN (g);∆ H: +270.3 kJ/mol
Add up all the reactions and remove the same compound from different sides :
2NH3 ⇒ N2 (g) + 3H2 (g) ∆ H: +91.8 kJ/mol
2CH4 (g) ⇒ 2C (s, graphite) + 4H2 (g) ∆H: +149.8 kJ/mol
H2 (g) + 2C (s, graphite) + N2 (g) ⇒ 2HCN (g) ∆ H: +270.3 kJ/mol
-----------------------------------------------------------------------------------------
2NH3(g) + 2CH4(g) ⇒ 2HCN + 6H2 ∆ H: 511.9 ⇒ :2
NH3(g) + CH4(g) ⇒ HCN + 3H2 ∆H:255.95
Which of the following is necessary to do a complete stoichiometric calculation? (5 points)
Add the nuclear masses of the products,
Divide the nuclear masses of the reactants,
Write the complete balanced chemical equation
Write the number of atoms in 1 mole of the product,
Answer:
Write the mole rato/Write the complete balanced chemical equation
Explanation:
there are two form of this question but only one of these answers will show up.
The stoichiometric calculations has been based on the writing of the balanced chemical equation. Thus option C is correct.
Stoichiometric calculations has been based on the chemical equation for a reaction. The stoichiometric chemical in a balanced chemical equation has helped in the calculation of the moles of the compounds involved in the chemical equation.
The complete stoichiometric calculations has been performed with the molecular mass of the compounds, and has been completed with the balanced chemical equation. Thus, option C is correct,
For more information about the stoichiometric calculation, refer to the link;
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how many atoms of hydrogen are in 420g sample of water
What are the methods of naming hydrocarbons?
Explanation:
Hey there!
Basically, we name hydrocarbon in two ways. They are;
Trival system of nomenclature: This system was used on past. They were given name knowing their sources from which hydrocarbon are obtained. On this naming we don't use scientific rules and structural values. For example; methane was named from marsh gas.IUPAC system of nomenclature: As the above method was not standard. IUPAC (International Union of pure and applied chemistry) improved the system and the started naming hydrocarbon. The IUPAC name of any compound contains two parts: root word and suffix. Example: Methane is named from root word Meth as it has one no.of carbon and suffix ane as it has single bonding.Hope it helps...
If your experiment did not seem to match the expected results, what did you learn from the experience?
Answer:
i learnt that the different result that i got can be prepared through my experiment. if that result is useful for anywork or for me then i can note down my procedure and use it again to get that result . And while noting it down i will know about the mistake that i did due to which i got different result and i can do correction of it in next time.
Both covalent-network solids and ionic solids can have melting points well in excess of room temperature, and both can be poor conductors of electricity in their pure form. However, in other ways their properties are quite different. a. Which type of solid is more likely to dissolve in water
Answer:
IonicEvidence: It can be proved by a simple experiment, sand doesn't dissolve in water but NaCl (table salt) does. (excluding cases like BaSO4 and sugar and amino acids)Cause: The electrostatic bonds among ions in a lattice only hold them together like two magnets with unlike poles facing each other. The water molecules can split them through the similar process with several molecules ganging up on them, the H+ parts of the molecules attracts the anion and O2- part; the cations. If this electrostatic attraction is big enough, the bonds between the solid's ions break (into separate ions). And so the solid dissolves. This is usually the case with most.
Why not covalent structures?: Sure, covalent solids have a low m.p and b.p for low intermolecular forces, the covalent bonds here are strong and cannot easily be 'pulled apart' by water molecules. They usually have stronger intermolecular forces than that of water.
But... if their intermolecular forces are weaker or similar, sure they can dissolve easily. Like any often-used alcohol (glacial).
How many formula units are in 4.56 moles of LiCl?
Answer:
In 4.56 moles of LiCl 27.46*10^23 formula units is present.
Explanation:
Formula units is defined as the empirical formula for any ionic, covalent and network solid compounds which are used as a single unit for stoichiometric calculations. Also It can be defined as the lowest whole number ratio of ions which can be represented in an ionic compound.
We are given
4.65 moles of Lithium chloride.
One mole of Lithium chloride has 6.022*10^23 unit Formula unit
In 4.56 moles of Lithium Chloride the formula unit will be
= 4.56*6.022*10^23
Formula units = 27.46 * 10^23
It is clear that in 4.56 moles of Lithium Chloride will contain 27.46*10^23 Formula unit.
Therefore in 4.56 moles of LiCl 27.46*10^23 formula units is present.
What are the coefficients?
Answer:
1, 3, 2
Explanation:
1 x N2 = N2
3 x H2 = H6
2 x NH3 = N2H6
which is balanced, I believe.
compare pure substance with mixture
Answer:
here
Explanation:
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Oxygen has 6 valence electrons, hydrogen has just one. Elements want to gain or lose electrons to complete their valence shells of eight electrons. How many atoms of hydrogen does a single atom of oxygen want to bond with? What is the name of this compound?
Answer:
water
Explanation:
Oxygen has 6 valence electrons, hydrogen has just one. Elements want to gain or lose electrons to complete their valence shells of eight electrons.
When oxygen combine with hydrogen it needed two electrons to complete the octet that's why two hydrogen atoms are combine with one atom of oxygen.
2H₂ + O₂ → 2H₂O
Both share the electron and form covalent bond because electrons are not equally share.
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.
For example:
In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive.
What is the mass of 2.486 * 10^{24} atoms of neon?
Select one:
a)83.33 g Ne
b)0.2046 g Ne
c)8.333 g Ne
d) 4.130 g Ne
Answer:
The answer is A 83.33 g Ne
Explanation:
Used Avogadros Law
A metalloid has physical and chemical properties of _____________
A: metals , nonmetals
B: metals and noble gases
C: halogens and noble gas
Answer:
Typical metalloids have a metallic appearance, but they are brittle and only fair conductors of electricity. Chemically, they behave mostly as nonmetals. They can form alloys with metals. Most of their other physical properties and chemical properties are intermediate in nature.
What is the independent variable in this reaction
Answer:
Explanation:
what wheres the answer???
What is the slowest type of mass movement?
Answer:
Creep
Creep is the slowest of all the mass movements and moves the most soil out of all the mass movements. The only way to detect soil creep is to observe the fences, buildings, and other surface objects that may be in that area. As the loosened soil moves slowly downslope, these objects will move along with the soil.
Explanation:
What else is produced during the combustion of butane, C4H10?
2C4H10 + 13O2 8________ + 10H2O
H2O
C4H10
CO2
O2
Another product: CO₂
Further explanationGiven
Reaction
2C₄H₁₀ + 13O₂⇒ 8__+ 10H₂O
Required
product compound
Solution
In the combustion of hydrocarbons there can be 2 kinds of products
If there is excess Oxygen, you will get Carbon dioxide(CO₂) and water in the product
If Oxygen is low, you'll get Carbon monoxide(CO) and water
Or in other ways, we can use the principle of the law of conservation of mass which is also related to the number of atoms in the reactants and in the products
if we look at the reaction above, there are C atoms on the left (reactants), so that in the product there will also be C atoms with the same number of C atoms on the left
2C₄H₁₀ + 13O₂⇒ 8CO₂+ 10H₂O
Answer:
is C. CO2
Explanation:
Which one sounds better "the reign of scar", or "Scar's Reign"
Answer:
i think
Explanation:
"the reign of scar" will sound better
I like "Scar's Reign". If you really like "the Reign of Scar" I suggest finding a synonym to "reign" that fits nicer. Good luck with... whatever you're doing. Hope this helps :)
3.Write the chemical equation for the reaction when methane burns in (2) (a) Sufficient supply of oxygen (b) Insufficient supply of oxygen
Answer:
the answer is god
Explanation:
because god created everything therefore hes the answer to everything
Answer:
(a) CH₄ + 2O₂ ----> CO₂ + 2H₂O
(b) 2CH₄ + 3O₂ ----> 2CO + 4H₂O
Explanation:
The burning of methane in an insufficient supply of air leads to incomplete combustion releasing carbon monoxide which is extremely poisonous and cause death.
When methane burnt in air or oxygen, it produces large amounts of heat, together with carbon dioxide and water vapour
What is the density of an object that has a mass of 500g and a volume of
10mL?
Please help!
Avogadro's number is the number of particles in one gram of a carbon-12 atom. (2 points)
True
False
(EDIT: Answer is false, just took the test)
Answer:
false
Explanation:
Avogadro's number : the number of units in one mole: 6.022 × 1023, which is the number of atoms in 12 grams of carbon-12.
Answer:
false
Explanation:
i took the test.