Answer:
B. pure substance
Explanation:
A chemical reaction is the only way to separate a(n) ✔ pure substance.
what elements react with mercury?
fluorine, F2, chlorine, Cl2, bromine, Br2, or iodine, I2
Which set of elements below is the most similar in chemical behavior?
OH, Be, SC
O Fr, Ra, Rf
O TI, V, Cr
O Be, Ca, Ra
Answer: Be, Ca, Ra
Explanation:
Elements are distributed in groups and periods in a periodic table.
Elements that belong to same groups will show similar chemical properties because they have same number of valence electrons.
Berrylium (Be) , Calcium (Ca) and radon (Rn) are elements which belong to Group 2. They have 4, 20 and 88 electrons respectively and contain 2 valence electrons each and thus can lose two electrons to complete their octet. Thus they will show similar chemical properties.
The chemical reactivity of elements is governed by the valence electrons present in the element.
define thermal and electrical conductivity, solubility, magnetism, melting and boiling points
Answer:
thermal conductivity: the rate at which heat is transferred by conduction through a unit cross-section area of a material, when a temperature gradient exits perpendicular to the area
electrical conductivity: the measure of the amount of electrical current a material can carry or it's ability to carry a current
solubility: the ability to be dissolved, especially in water
magnetism: a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects
melting point: the temperature at which a given solid will melt.
boiling point: the temperature at which a liquid boils and turns to vapor
Explanation:
hope this helps :D pls mark brainliest :D
Scientists can engage in many different activities in many different sequences.
Question 2 options:
when using the scientific method.
when convincing peers they have all the answers.
when proving the existence of aliens.
when explaining and documenting their work
Answer:D-when explaining and documenting their work
Explanation:I took the k-12 test and got it right!:) Hope this helps!!!!
Scientists can engage in various activities in various sequences. It can be best explained by documenting and explaining their work. Thus, option D is correct.
What is the scientific method?The scientific method has been a series of events that uses observed phenomena to conduct research by testing the hypothesis that raises the question. It conducts the experiment and reaches the results to conclude the findings.
In various scientific sequences, scientists can be engaged at a time similar to explaining and documenting the work involves representation of the proper rationale and its deep and thorough explanation so to justify the hypothesis and its accountability.
Therefore, option D. the explanation and documentation are the various activities involved in different sequences.
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mass number is the number of protons and neutrons in the nucleus of an isotope . how many protons in an oxygen-18 atom ?
Answer: Oxygen - 18 atom contains 8 protons.
Explanation:
The number of protons is the same as the atomic number. In isotopes, only the neutrons vary, but the protons always remain the same.
A solution is made
by dissolving
29 g of sodium lithium chloride
in water to a final volume of
202 mL solution.
What is the weightweight % or percent by mass of the somute
percent by mass of the solute?
Answer:
99.3%
Explanation:
The percent by mass of the solute can be expressed as:
% mass = [tex]\frac{MassSolute}{MassSolute+MassSolvent}[/tex] * 100%And for this problem:
Mass of Solute = Mass of sodium lithium chloride = 29 gMass of Solvent = Mass of WaterSo to calculate the percent by mass first we need to calculate the mass of water, to do so we use its density (1 g/L):
202 mL is equal to (202/1000) 0.202 L.Density water = mass water / volume
1 g/L = mass water / 0.202 LMass water = 0.202 gNow we have all the data required to calculate the % mass:
% mass = [tex]\frac{29g}{29g+0.202g}[/tex] * 100 % = 99.3%Answer: 14.3
Explanation:
What’s the answer???
Answer:
D
Explanation:
Answer:
C - Up and Down in a Circle
Explanation:
Waves are actually energy passing through the water, causing it to move in a circular motion. When a wave encounters a surface object, the object appears to lurch forward and upward with the wave, but then falls down and back in an orbital rotation as the wave continues by, ending up in the same position as before the wave came by.
I need to know what the matter is of a tree
Answer:
heterogenous mixture i believe.
Explanation:
what is the basis for the classification of organic compounds?
Answer:
organic compounds are classified based on functoin group
Explanation:
functional group is part of molecule or compound that determine the properties of that molecule or compound.
In chemistry, organic compounds are substances that have a covalently linked carbon atom. These compounds are classified based on the functional group and structures.
What are organic compounds?Organic compounds are said to be the compounds that have the presence of the carbon atom/s linked to the other atoms including nitrogen, oxygen, and hydrogen through a covalent bond.
The organic compounds are classified based on their structures and functional groups attached to their side chains. The functional groups include alkynes, alkenes, alcohols, carbonyl, nitriles, amines, etc.
The compounds can also be categorized based on the open or closed chain structures that can be homocyclic or heterocyclic. Further, the compounds can be aromatic or alicyclic.
Therefore, organic compounds are classified based on their functional groups and structures.
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What best describes what models are used for?
A. Models are used as substitutes for compounds.
B. Models are used to explain how something works.
C. Models are used to perform experiments.
D. Models are used to develop new technologies.
Explanation:
is b or c but i think asnwer is b
The correct statement is " Models are used to explain how something works."
What is model?To introduce specific content, models might be employed. A model can help students learn crucial words and create a setting in which they can investigate pertinent processes.
Models can be used to improve explanations, promote discussion, make predictions, present graphical images of abstract concepts, and generate mental models in research.
Therefore, Models are used to explain how something works .
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I need help:< for my chemistry class we have to write the equation at first it says "Expand the right side by multiplyig each term. that is... 5 x 27 = 135 and 5 x 3a = 15a
so i get "2a = 135 -15a i just want to know how i have to write the equation because i suck at Math i'm so bad at it. Pls gave me some help!!!
The value of 'a' is 7.9
Chemical equations - chemical equations are symbolic depictions of chemical reactions where the reactants and products are stated in terms of their respective chemical formulae.
Balancing of chemical equation is necessary because the law of conservation of mass states that during a chemical reaction, matter cannot be generated or destroyed. This is only conceivable if the total number of atoms on the reactants' and products' sides is identical. A chemical reaction should therefore always be in balance.
According to the given equation-
2a = 135 - 15a
2a + 15a = 135
17 a = 135
a = 135/ 17
a = 7.9
You can solve it by simply transferring the variables on one side and the constants on the other side. When you transfer -15 a on the left side it becomes =15a. now, 2a + 15 a is 17 a.
For taking out the value of 'a' simply divide 135 by 17.
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How did scientists discover that rocks farther away from the mid-ocean ridge were older than those near it?
a. by measuring how fast sea-floor spreading occurs
b. by observing eruptions of molten material on the seafloor
c. by determining the age of rock samples obtained by drilling on the seafloor
d. by mapping rocks on the seafloor using sonar
Scientists discover that rocks farther away from the mid-ocean ridge were older than those near it by C. determining the age of rock samples obtained by drilling on the seafloor.
According to the scientists, it was noted that new oceanic crusts were formed at the mid-ocean ridges. When it cools down, then the magnetic field during its formation is recorded.
The magnetic stripes become older when they move away from the mid-ocean ridge. The geologic dating technique was used in the seafloor rocks. It was found that the youngest rocks were at the mid-ocean ridges while the rocks get older due to their distance from the ridge crest.
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Explain why, in a balanced chemical equation C + O2 CO2, we know that 1 gram of C will not react exactly with 1 gram of O2.
Answer:
See the answer below
Explanation:
From the equation, 1 mole of C requires 1 mole of O2 for a balanced reaction.
1 g of C will not exactly react with 1 g of O2 because the 1 g of each of the reactants contain different amounts of the substance.
The amount (in moles) of a substance is the mass of that substance divided by the molar mass.
Hence, 1 g of C will contain 1/12 moles of the substance while 1 g of O2 will contain 1/32 moles of the substance.
_Cl2 + _NaBr → _NaCl + _Br2
Answer: 1,2,2,1
PLEASE HELP CHEMITRY!
What happens to the binding energy of lighter elements when they undergo fusion?
What is the most stable nucleus (the one with the highest binding energy)?
What happens to the binding energy of elements like uranium when they undergo fission?
Why does the fusion of elements beyond iron in our universe require a supernova? Use this diagram to explain your answer.
Answer:
.
Explanation:
Answer:
1) In fusion reactions, two light atomic nuclei fuse together to form a heavier nucleus. In doing so, they release a comparatively large amount of energy that arises from the binding energy, creating an increase in temperature of the reactants.
2) iron-56
3) When a large, fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission. However, one neutron does collide with an atom of uranium-235, which then splits and releases two neutrons and more binding energy.
4) Iron cannot release energy by fusion because it requires a larger input of energy than it releases. This energy blows the outer layers of the star off into space in a giant explosion called a supernova (plural: supernovae.)
have you tried G o o g l e
put the following in order from LARGEST TO SMALLEST nuclueus,molecule,electron,atom,proton and a teacher
Answer:
electron, proton, nucleus, atom, molecule teacher
Select all that apply tomitosis (Choose 4)
A
Muscle cells reproduce this way
B
Does not require a male and female to reproduce.
C
Results in the production of gametes
D
Final cell is identical to parent cell
E
Repairs skin following sunburn
F
Final cell has only half of the parent's DNA
G
Requires a male and female to reproduce
H
Results in the production of haploid cells.
is graph paper a homogeneous or heterogeneous mixture
Answer:
There is no chemical symbol for paper since it is not an element but rather a mixture of several different compounds. Mixtures in two or more phases are heterogeneous mixtures.
Explanation:
Is Sucrose a ionic or covalent bond
Answer:
covalent bond
Explanation:
hope this helps :D
How many sucrose molecules will be in 250 grams
We will need to know Avogadro's number and the molar mass of sucrose for this problem to do dimensional analysis.
Avogadro's number: 6.022 × 10²³ moleculesMolar mass of sucrose: 342.2965 g/mol250g × [tex]\frac{1 mol}{342.297g}[/tex] × [tex]\frac{6.022 * 10^{23} molecules}{1 mol}[/tex] = 4.398 molecules
There are 4.398 sucrose molecules in 250 grams of sucrose.
HELP PLEASE
What makes up most of an
atom's volume, and where is it located?
Answer:Accounting for the sizes of protons, neutrons, and electrons, most of the volume of an atom—greater than 99 percent—is, in fact, empty space. ... The electrons that surround all atoms are negatively charged and cause atoms to repel one another, preventing atoms from occupying the same space.
Explanation: hope this helped
which would indicate the water in a lake is not safe for drinkinh
Answer:
Explanation:
Alge. Waste and dead things
what is wrong with you how cant you do this I'm not being mean I'm just asking dont answer if you dont want to its ur life
ASAP pleaseee and Thankyou
Answer:
I know the answer, but it is hard to explain
Explanation:
yIt easy u but the single letter in the outside boxes. Then u but the one in the middle box. But the BB in one corner. then but bb on the opposite corner. Then but Bb on the other box.
Answer:
father.....Bb
mother.....bb
offspring, 50%Bb brown eyes ,50%bb blue eyes
If someone gave you flour, sugar, butter, eggs, baking soda, and salt, what could those ingredients turn into?
Answer:
You can make Cake CAke Cake Cake and other stuff too Ig
Explanation:
Planets that orbit closer to the Sun than Earth have ____ years than we do.
Answer:
Well, it depends on where they are orbiting! Planets that orbit closer to the Sun than Earth have shorter years than Earth. Planets that orbit farther from the Sun than Earth have longer years than Earth.
Lets say a giant radioactive monster is attacking
Phoenix. This monster is so radioactive and big the air in
Feels easily over 120°. Is this an endothermic or
exothermic reaction?
Answer: exothermic reaction
The monster is releasing heat energy to the environment surrounding it. The term "exo" means "outside".
In contrast, an endothermic reaction is one where energy is absorbed from the environment to cool down the surrounding air.
calculate the mole fraction of alcl3 in a solution made by dissolving 195 g of alcl3 in 240 ml of water
The mole fraction of 195 g AlCl3 in 240 mL of water is 0.099.
Mole fraction is the ratio of the number of moles of a particular component to the total number of moles in the mixture. To determine the mole fraction of AlCl3, the mass of AlCl3 will be converted to moles and the number of moles of water must be determined. Since the amount of water used is expressed in volume, we will be using the density of water to determine the mass of water for a given volume.
Solving for the moles of AlCl3:
moles AlCl3 = mass AlCl3 / molar mass of AlCl3
moles AlCl3 = 195 g / 133.33 g/mol
moles AlCl3 = 1.4625 mol
Solving for moles of water:
A commonly used density of water is 1 g/mL.
240 mL of water * (1 g/mL) = 240 g of water
moles water = mass water / molar mass water
moles water = 240 g / 18.02 g/mol
moles water = 13.32 mol of water
Mole fraction = mol AlCl3 / ( mol AlCl3 + mol water)
Mole fraction = 1.4625 / {1.4625 +13.32)
Mole fraction of AlCl3 is 0.099
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Which of the following explains the VSEPR geometry of a carbon tetrachloride molecule? (5 points)
:Č:
:Č-c- CI:
:CI:
OIt is bent because there are four bonded pairs around carbon.
OIts tetrahedral because there are four bonded pairs around carbon.
OIt is bent because there are two bonded pairs and two lone pairs around carbon.
OIts tetrahedral because there are two bonded pairs and two lone pairs around carbon.
Answer:
B) It is bent because there are four bonded pairs around carbon.
Explanation:
Since carbon forms a single bond with all four chlorides (four domains), the shape and geometry will both be tetrahedral. There are no lone pairs of electrons that cause the shape to appear bent.
Its tetrahedral because there are four bonded pairs around carbon. This explains the VSEPR geometry of a carbon tetrachloride molecule. Therefore, the correct option is option B.
What is VSEPR geometry?
The acronym VSEPR (pronounced "vesper") is frequently used to refer to the model known as Valence Shell Electron Pair Repulsion Model. The model essentially predicts the shape of molecules. In particular, organic compounds and polyatomic ions' bonding & molecular geometry are examined by VSEPR models. Almost all compounds with a central atom which is not a metal can benefit from it.
Due to their two-dimensionality, Lewis structures can only reveal the quantity and kind of atom-atom bonds. The 3-D shapes of ions and molecules are predicted by the VSEPR model, but it is unable to offer any exact details on the bond length and the bond itself. Its tetrahedral because there are four bonded pairs around carbon. This explains the VSEPR geometry of a carbon tetrachloride molecule.
Therefore, the correct option is option B.
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on this graph below, the independent variable is
What happens when a wave hits an object?
the wave is reflected
the wave continues on
the wave is interfered with
the wave stops