Describe the two categories used to classify physical changes.
Answer:
Physical changes can be classified as reversible or irreversible. Melting is an example of a reversible physical change.
Explanation:
whats the formula for lithium nitride
Answer:
Lithium nitride. Trilithium nitride. 26134-62-3. Lithium nitride (Li3N) Li3N.
What is an example of a polar molecule
Question 8 options:
A molecule that is made of ionic bonds like NaCl.
A molecule that is made of covalent bonds like sugar.
A molecule made of covalent bonds that has partial positive and partial negative charges in different areas of the atom.
A molecule made of ionic bonds that has strong positive and strong negative charges in different areas of the molecule.
Answer:
The two main classes of molecules are polar molecules and nonpolar molecules. Some molecules are clearly polar or nonpolar, while others fall somewhere on the spectrum between two classes. Here's a look at what polar and nonpolar mean, how to predict whether a molecule will be one or the other, and examples of representative compounds.
Explanation:
so its c
An example of polar molecule is a molecule made of covalent bonds that has partial positive and partial negative charges in different areas of the atom.
What is covalent bond?
Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
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PLS HELP: Endocrine Organs Crossword
Why is the Milky Way considered a galaxy
Answer:
Explanation:
All the stars we see in the night sky are in our own Milky Way Galaxy. Our galaxy is called the Milky Way because it appears as a milky band of light in the sky when you see it in a really dark area.
Answer: it is
Explanation: A galaxy is a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction, plus there are 100 billion planet in it.
How many moles of iron are in 50.0g of iron? How many iron atoms are in 59.0g of iron?
Answer:
[tex]50.0 \div 59.0 = 10[/tex]
right
Most elements are ____________. The _____________ elements on the left of the stair-step line on the ______________ of Elements are metals or metal-like _____________. Some of the physical properties of metals are ______________ (shininess) and ___________ density. They are also good conductors of ___________ and ______________. Metals can be hammered into __________sheets.
Answer:
metals, 88 , periodic table , luster , heat, electricity , thin, right, opposite , appearance , luster , malleable , ductile, opposite , shiny, moderately
Explanation:
metals, 88 , periodic table , luster , heat, electricity , thin, right, opposite , appearance , luster , malleable , ductile, opposite , shiny, moderately Is the answer.
(Hope this helps can I pls have brainlist (crown)☺️)
_____ is the tendency of an atom in a compound to attract electrons (F is super attractive and Fr is super unattractive).
The answer is Electronegativity.
What is the role of cellular respiration in organisms?
to provide energy for photosynthesis
to provide energy for breaking apart fuel molecules
to provide energy for making oxygen
to provide energy for cell activity
Answer:
C. sorry if I'm wrong ...................
When pyridine is treated with a mixture of nitric and sulfuric acids, the major product is:.
Answer: 3-nitropyridine
Explanation:
What structural characteristic do all of the atoms within a group (vertical columns) have in common?
Answer:
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
hope this helps
Explanation:
Each column is called a group. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements.
does anyone know how to find the electron configuration of an element without using a periodic table?? group and period is already given
Valence electrons are electrons in the ? of an atom.
Answer:
Valence electrons are the outermost of electrons.
Explanation:
valence electrons are the outermost electrons of an atom located in the shell/ orbit
bonding and kinetic energy quick check
1. The internal energy within a system associated with the motion of particles and that can be added to a substance is called (1 point)
o temperature
O kinetic energy
O thermal energy
O electrostatic forces
2. which statement describes the effect of adding more energy to a system, assuming a phase change does not occur?
0 the particles within the system will have greater motion and the temperature will increase
0 the particles within the system will have greater motion and the temperature will be grace
0 particles within the system will have less motion and the temperature will increase
0 the particles within the system will have less motion and the temperature will decrease
3. which statement correctly describes how a tractions that holds particles break
0 attractions occur due to gravitational forces when particles move fast enough these forces can no longer keep particles together
0 attractions due to Electrostatic forces when particles move fast enough these forces can no longer keep particles together
0 attractions due to electrostatic forces when particles have low enough energy these forces can no longer keep particles together
0 attractions occurred due to gravitational forces when particles have low enough energy these forces can no longer keep particles together
4. Which statement explains why a rubber band analogy is not a perfect comprehension for Bonds in a substance when considering phases change
0 for a phase change from solid to liquid the bonds do not break completely and particles can still slide past each other
0 for a phase change from liquid to gas the bonds do not break completely the particles can still slide past each other
0 for a phase change from liquid to gas the bonds break completely and of particles can independently of each other
0 phase change from solid to liquid the bond breaks completely particles can move independently of each other
5.the boiling point of benzene is 80°C. which pair of samples will have the same average kinetic energy of benzene molecules?
0 two samples of gaseous benzene, at 80°C and the other 90°C
0 two samples of liquid benzene, one at 70°C and the other at 80°
0 a sample of liquid benzene at 70°C and a sample of gaseous benzene at 90°C
0 a sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°celectric
When energy is added to a system during phase change, the particles move faster.
When a substance is heated, the internal energy within a system associated with the motion of particles and that can be added to a substance is called thermal energy.
During a phase change, when more energy is added to the system, the particles within the system will have greater motion and the temperature will increase.
The attractions that hold molecules together are electrostatic forces. The correct statement about the attractions that hold particles is that attractions between particles break when attractions due to Electrostatic forces when particles move fast enough these forces can no longer keep particles together.
Rubber band is not a perfect comprehension for Bonds in a substance when considering phases change because for a phase change from liquid to gas the bonds do not break completely the particles can still slide past each other.
The pair of samples that will have the same average kinetic energy of benzene molecules is a sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°C.
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Which of the following shows a valid combustion reaction?
2Al + 2O2 → 2AlO + O2
C2H4 + 3O2 → 2CO2 + 2H2O
2CH4 + O2 → 2CO + 4H2
Ca + O2 → CaOH
Answer: C2H4 + 3O2 → 2CO2 + 2H2O
Explanation:
2Al + 2O2 → 2AlO + O2 Not Balanced Properly: 2Al + O2 = 2AlO
C2H4 + 3O2 → 2CO2 + 2H2O Looks Good
2CH4 + O2 → 2CO + 4H2 Not Correct: CO should be CO2
Ca + O2 → CaOH Not Balanced and No source for the H
Answer:
2H4+3O2 →2CO2+2H2
Explanation:
What is the chemical formula for ammonium carbonate?
The letter for element Q stands for "qualium." What would the compound in 1a be called?
(1 A)
Answer:
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Which would best describe the way an organism reacts to other organisms or to its
environment?
A. Instinct
B. Behavior
C. Conditioning
D. Imprinting
Answer:
Explanation:
Behavior
Help
What is the correct orientation of the bar magnet, based on the magnetic field
lines shown?
A. South pole on the top edge and north pole on the bottom edge.
B. North pole on the top edge and south pole on the bottom edge
C. South pole on the left end and north pole on the right end
D. North pole on the left end and south pole on the right end
Answer:
b
Explanation:
north is up south is bottom
Answer:
C. South pole on the left end and north pole on the right end
Explanation:
From the figure, we can conclude that the poles of the magnet are on either sides of the magnet
Therefore, options 1 and 2 are excluded
It is a convention that the magnetic field lines move out of the north pole of a magnet and into the south pole of the magnet
From the figure, we can see that the magnetic field lines are moving out from the right end and into the left end
This means that the north pole is at the right end and that the south pole is at the left one
help me please the subject is siecnce
Answer:
okay your question in science
What is the frequency of light with a wavelength of 450 nm?
Answer:
The frequency of blue light that has a wavelength of 450 nm is 6.7×1014 6.7 × 10 14 Hz.
Explanation:
BRAINLIEST?
Which one of the following would form a precipitate when mixed with LiOH?
A) KNO3
B) NH4Cl
C) Ca(C2H3O2)2
D) ZnBr2
Answer:
ZnBr2
Explanation:
KNO3 + LiOH -------> no reaction
This is because KNO3 and LiOH completely ionize.in water and form neutral solutions.Since both are neutral no reaction occurs
NH4Cl + LiOH -----> NH3 (aq) + H2O (l) + LiCl(aq)
None of the above products are precipitates
Ca(C2H3O2)2 + 2LiOH -----> Ca(OH)2 (aq) + 2LiC2H3O2 (aq)
ZnBr2 + 2LiOH -----> Zn(OH)2 (s) + LiBr2 ( aq)
Zn(OH)2 thus formed is a white precipitate
However when excess LiOH is added Zn(OH)2 precipitate will dissolve to give a clear solution of Li2ZnO2 .
You can remember this by the fact that Na,K,Rb,Cs,Ca,Sr,Ba hydroxides are soluble in water and all other hydroxide are precipitated in water
Zn(OH)2 (s) + 2 LiOH ------> Li2ZnO2(aq) + 2 H2O ( l)
The only compound that will form a precipitate with LiOH would be ZnBr2
Precipitation reactionsThese are double displacement reactions in which precipitates are produced. Precipitates are insoluble solids formed from the combination of ions in aqueous solutions.
In this case, a reaction between LiOH and ZnBr2 would be as follows;
2LiOH + ZnBr2 ----------> 2LiBr + Zn(OH)2 (s)
Zn(OH)2 is an insoluble salt and will precipitate out in the solution.
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What is oxidation state?
Answer:
a number assigned to an element in chemical combination which represents the number of electrons lost (or gained, if the number is negative), by an atom of that element in the compound
Explanation:
sodium, magnesium, iron is zero.
The definition of oxidation state is as follows: Oxidation state is a number given to the atom of an element when participating in a chemical reaction.
OXIDATION STATE:The atoms of elements are not always neutral i.e. carry no charge. They sometimes carry either positive or negative charges to become ions. Ions can either be cations (positively charged) or anions (negatively charged). The amount of charges are represented by numbers placed as a superscript in front of the element involved. These superscript charge assigned to a corresponding element during a chemical reaction is called oxidation state. The oxidation state of an element portrays the number of electrons gained or lost during the reaction.Therefore, oxidation state can be defined as a number given to the atom of an element when participating in a chemical reaction.
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which of these is a rough approximation of the cogito?
Given the Latin meaning of the cogito, we can confirm that it is roughly translated and summarized by the phrase "I think, therefore I am".
Cogito, ergo sum or "The Cogito" is an extremely popular, well-known philosophical phrase credited to Rene Descartes. This Latin phrase is roughly translated as "I think, therefore I am", which appeared originally in "The Principles of Philosophy", and was later translated to a variety of languages in an attempt to reach a wider public, most notably into Latin.
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what is an environmental result from burning fossil fuels?
Answer:
The burning of fossil fuels contributes to the addition of greenhouse gases to the atmosphere. These gases trap thermal energy in the Earth's atmosphere.
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because: __________
a. cobalt is a stronger reducing agent than iron
b. iron is a stronger reducing agent than manganese
c. cobalt exhibits more metallic character than either iron or manganese in the iron-manganese alloy
Rusting is an electrochemical reaction. Iron rusts faster when alloyed with cobalt than when alloyed with manganese because, in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
An alloy is a combination of two metals. There are various reasons for producing alloys such as greater tensile strength, corrosion resistance and improved aesthetic appearance.
When iron is alloyed with cobalt, the iron rusts faster than pure iron because iron is rendered the anode and cobalt is rendered the cathode. When the iron is alloyed with manganese, it rusts more slowly than pure iron because in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode.
Missing parts;
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because
(1) cobalt is a stronger reducing agent than iron
(2) iron is a stronger reducing agent than manganese
(3) cobalt exhibits more metallic character than either iron or manganese
(4) in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
(5) in the iron-cobalt alloy, cobalt is rendered the anode and iron is rendered the cathode
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What is infrared energy? simplify it
Answer:
It is a type of radiant energy that's invisible to human eyes but that we can feel as heat.
Which is an example of a physical change?
A) Mixing blue and yellow paint to create green paint
B) Adding water and yeast to bread dough in order to make it raise.
C) Mixing two liquids together in a test tube and the tube becoming warm.
D) Adding a piece of chalk containing calcium carbonate to a glass of mild acid causing the information of a foam of bubbles.
how well did the landmases fit together this time
Answer:
The theory of continental drift is most associated with the scientist Alfred Wegener. In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other. He called this movement continental drift.
Explanation:
Please help This is for my chemistry class and I need to get it done but I’m lost and need answers
Answer:
chlorine is a non metal.
sodium is a alkali metal.
helium is a noble gas.
nickel is a transition metal
