Answer:
Explanation:
Saturated solution
Dana is trying to determine if an unknown sample is a pure substance or not. The sample has a cloudy white color, and it seems evenly mixed throughout. The sample is a liquid with high viscosity. Dana tried separating the sample with a magnet with no effect. When Dana filtered the sample, larger granules of the sample were left behind in the filter. What evidence allowed Dana to conclude that the sample is NOT a pure substance?
It has a cloudy white color.
The liquid has high viscosity.
Dana tried separating the sample with a magnet with no effect.
Dana filtered the sample and larger granules of the sample were left behind.
Answer:
Dana filtered the sample and larger granules of the sample were left behind.
Explanation:
If a substance is pure, it will have a uniform composition throughout. It will not separate into particles of various sizes.
One of the characteristics of pure substances is that they are homogeneous. A mixture is definitely made up of particles of various sizes.
Since the particles was filtered and larger granules were left behind, the sample has been separated by a physical method (filtration). Only a mixture can be separated by physical methods. It is not a pure substance.
1. Under what conditions can potassium bromide conduct electricity?
A only when melted
B. when melted or dissolved in water
C. only when it is in crystal form
D. only when dissolved
Answer:
potassium bromide can only conduct electricity when in an aqueous solution due to the electrostatic force between the ionic bonds
The potassium bromide can conduct electricity when melted or dissolved in water. Therefore, option (B) is correct.
What are ionic compounds?The crystalline solids which are formed by closely packed ions of opposite charge are called ionic compounds. In ionic compounds, the ions are connected with each other by ionic bonds in solis state.
The elements which can gain or lose electrons to attain their nearest noble gas configuration participate in the formation of ionic compounds. The solid ionic compound cannot able to conduct electricity.
In the melted state, the ions of K⁺ and Br⁻ can move from their fixed positions. Therefore, the KBr can conduct electricity when melted or dissolved in water.
The ionic compounds are able to conduct electricity in melted or dissolved in water. Because only in these states the ins can move freely while in the crystalline state the ions cannot move freely to conduct electricity.
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Which term refers to the ability to do work? O energy O power force O motion
Please I have a 50 question Exam
Answer:
the correct answer in energy
Explanation:
The term refers to the ability to do work is energy. The correct option is A.
What is energy?Energy is the quantitative property that is required by the body to do some work. It is a conserved quantity, but can not be created or destroyed.
Animals and plants get energy from food.
Thus, the correct option is A. energy.
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A copper rod takes up 75 mL of space. With a density of 8.96 g/mL, what is the mass of the rod
Compare a mixture and a compound. How are they alike?
Contrast a mixture and a compound. How are they different
Answer:
1.Difference.
Mixtures are physically combined and can be separated by physical means while compounds are chemically combined and are separated by chemical means.
2.Mixtures do not have mixed boiling and melting points while compounds have mixed boiling and melting points.
2.Similarity.
Both mixtures and compounds are composed of two or more substances or elements combined.
Both can be separated.
Mixtures and compounds are alike in the following ways:
1. Both mixture and compound contains two or more substances.
2. Both mixture and compound can be separated.
3. Both mixture and compound have physical properties.
Differences between mixture and compound:Mixtures and compounds are different in the following ways:
1. A mixture contains two or more substances that are not chemically combined together while a compound contains two or more substances chemically combined together.
2. A mixture can be separated by physical methods while a compound can only be separated by chemical methods.
3. Mixtures can not be represented using a chemical formula. Compounds can be represented by chemical formula.
4. Examples of mixtures include: milk, kerosene in water etc. Examples of compounds include water, sodium chloride etc
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1. What is the electron configuration for zirconium?
1s 2s 2p 3s 3p 3d 10 452 4p 532 44?
132 232 2p 3s 3p 432 3410 4p6 552 44²
O 132 232 2p 3s 3p 3040 4p 58% 42%
O 1:2 232 2p 3s 3p 452 300 dp" 4d?
Answer:
nose Inglés
bssnsnnsnsnsnsnsks
Answer: I think its the first won
Explanation:
(copped and pasted from website)
Zirconium
Electronic configuration
1s22s22p63s23p63d104s24p64d25s2
When their is a new moon the sun and moon are on the same side of the earth this leads to a combination of gravitational forces causing usually high tides called
Neap tides
Low tides
Supreme tides
Spring tides
Answer:
Low Tides
Explanation:
Took the test
100%
Which of the following would most likely cause a chemical reaction to occur at a slower rate?
Answer:
D
Explanation: When you chill a substance when it is mixed with another substance, ( chilled vinegar mixed with sodium bicarbonate will react slower for instance) it reacts slower do to the molecules slowing down when chilled.
[tex]\huge\boxed{Option D}[/tex]
Solution:a liquid mixture in which the the solute which is in a smaller proportion is uniformly distributed within the the solvent which is the major component is called a solution.
_____________________________________Option AStirring the substance together vigorously:It increases the rate of reaction, because when we stir the solute in the solution, the mixed solute particles are distributed more further than when they are left stationary, making the environment (which surrounds the solute) less concentrated by the dissolved solute thus the rate increases and more solute is mixed.
Option BDissolving the reacting substance in water:No, A reacting substances in water are those which can react with water that are Ionic metal. Water is made of ions [tex]H^+ and OH^-[/tex]. Substances(solute), they mix or dissolve more because Solutes ions interact with the ions of a water(solvent), thus breaking the bonds between the solute and then ions of solute form bond with the ions of water. Thus the rate increases in water.
Option CIncreasing the temperature increases the rate of reaction:No, because by the increase in temperature, the kinetic energy of more molecules of a substance increase which results in reaching the threshold energy(minimum energy required by the molecules to change into product) of more molecules. So less molecules are left with low energy.
Option DDecreasing the temperature decrease the rate of reaction.Yes, the rate of reaction decreases because the molecules are slower and collide less. Less molecules make the effective collisions due to which the kinetic energy of molecules is less, so less molecules make up to the threshold energy. So decrease in temperature lowers the rate of the reaction.
_____________________________________Best Regards,'Borz'You
2. An all natural mosquito repellent
is trying to make its way into the
market. One arm is sprayed with the
repellent and one arm is not sprayed
with anything. After 3 hours, the
number of mosquito bites is counted. What is the control group
Answer:
The arm that was not sprayed with anything
Explanation:
The control group would be the arm that was not sprayed with anything.
The control group during an experiment is a group that forms the baseline for comparison in other to determine the effects of a treatment. The control group does not include the variable that is being tested and as such, it provides the benchmark to measure the effects of the tested variable on the other group - the experimental group. In this case, the experimental group would be the arm that was sprayed with the repellent.
1. How many valence electrons does lodine
have?
How are convalent molecules named?
Covalent compounds are named by using numerical prefixes to identify the number of atoms in the molecule. E.g. Mono, Di, tri, tetra, etc.
In the naming, never use mono- for the first element.
The first element keeps its name.
The second element always end in the suffix -ide.
Drop the double vowel for the prefix and the element of the second element in the compound.
Hope this helped!
Help pleasee I need help to write the formulas i’m so lost
Answer:
NH4
Explanation:
Level 1: You are attempting to identify an unknown substance. Use the table to
answer the questions below.
Substance
Formula
Mass,
Color
Physical
State
Density Boiling
. (g/cm) Point,
Methane
CH
16.0
Gas
Colorless
0.423
-161.5
Ammonia
NH,
17.0
Gas
Colorless
0.70
-33
Unknown
???
???
???
???
???
???
Propane
CH
Gas
Colorless
0.493
-42.1
Bromine
Br.
159.8
Liquid
Red
4.04
58.8
Lithium
Li
6.94
Solid
0.534
1342
Silvery,
white
metal
Magnesium Mg
24.3
Solid
1.74
1090
Silver,
white
metal
A chemist titrates 100.0 mL of a 0.3065 M aniline (C6H5NH2) solution with 0.5774 solution at 25 . Calculate the pH at equivalence. The of aniline is .
Answer:
4.91
Explanation:
From the given information:
The millimoles of aniline = 100* 0.3065 = 30.65
30.65 millimoles HNO3 must be added to reach the equivalence point.
30.65 = V x 0.5774
V = 30.65/0.5774
V = 53.08 mL HNO3 must be added
Thus, total volume = 53.08 + 100 = 153.08 mL
[salt] = 30.65 / 153.08 = 0.20022 M
At equivalence point :
pOH = 1/2 [pKw + pKb + logC]
pOH = 1/2 [14 + 4.87 + log 0.20022 ]
pOH =9.086
pH = 14 - 9.086
pH = 4.914
pH ≅ 4.91 to 2 decimal places.
do you think the mass of the products after the chemical reaction would be greater than, less than, or the same as the mass of the reactants before the chemical reaction?
It will be the same, as explained by conservation of mass.
hope this helped!
What is the mass of HF produced by three reaction of 3.0 10 to the 23 molecules of H2 with excess F2
Answer:
It is 20. g HF
Explanation:
H2 + F2 ==> 2HF ... balanced equation
Since the question is asking us to find the mass of product formed, we will want to first convert the molecules of H2 into moles of H2 (we could do this at the end of the calculations, but it's just as easy to do it now).
moles of H2 present (using Avogadro's number):
3.0x1023 molecules H2 x 1 mole H2/6.02x1023 molecules = 0.498 moles H2
From the balanced equation, we see that 1 mole H2 produces 2 moles HF. Therefore, we can now find the theoretical mass of HF produced from 0.498 moles H2:
0.498 moles H2 x 2 moles HF/1 mol H2 = 0.996 moles HF formed.
The molar mass of HF = 20.01 g/mole, thus...
0.996 moles HF x 20.01 g/mole = 19.93 g HF = 20. g HF formed (to 2 significant figures)
The breaking and forming of bonds between atoms in substances results in changes in the _______ contained in the substances.
Answer:
Electrons
Explanation:
The breaking and forming of bonds between atoms in substances results in changes in the number of electrons in the substance.
Atoms combined in order to share, gain or lose electrons for it to be stable. The noble gases have a set up configuration which makes them stable. All atom tend to mimic the noble gases.Mention any three ways of making salt. (please help me Asap)
PLSSSSSSSSSSSSSSSSSSSSSSSSSS HELP
Which of the following best describes physical weathering? (4 points)
A series of chemical changes that wears away at rocks
The movement of rocks from one area to another
Any large-scale event such as volcanic eruptions or earthquakes
A process that breaks down large rocks into smaller piec
Answer:
D. A process that breaks down large rocks into smaller pieces.
Explanation:
Physical weathering if referred to the process of rocks breaking apart without changing their chemical composition. If you look at the other answers, none of them match the description of physical weathering.
Answer:
A process that breaks down large rocks into smaller pieces.
7. Which of the following is unlikely to
happen to zinc?
A) It is rolled into sheets.
B) It is used to coat a steel hull.
C) It is used in a battery.
D) It is used as an insulator.
Answer:D) it is used as an insulator
Explanation:
Which of the following is true with respect to energy in a closed system?
A.
Energy can be destroyed, but cannot be created.
.
Energy can be created, but cannot be destroyed.
B.
OOOO
C. The system's kinetic energy must equal its potential energy.
D.
The total amount of energy in the system always stays the same.
Answer:
D. The total amount of energy in the system always stays the same
Explanation:
In the closed system, the total amount of energy in the system always stays the same.
What is closed system?Closed system is a arrangement in which exchange of energy or any material is restricted.
If any reaction is carried out in a closed system then energy of the system may convert from internal energy to potential or from potential to kinetic energy. But the total energy of the closed system is always remain same as before and after the reaction.
Hence option (D) is correct.
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which element requires the least i.e. potassium or gallium why
Answer:
Potassium
General Formulas and Concepts:
Chem
Reading a Periodic TablePeriodic TrendsIonization Energy - energy required to remove an electron from a given elementCoulomb's LawShielding EffectZ-effective and Forces of AttractionExplanation:
The Periodic Trend for 1st Ionization Energy is increasing up and to the right. That means He would have the highest I.E and therefore take the most amount of energy to remove an electron.
Potassium and Gallium are both in Period 4. Potassium is element 19 and Gallium is element 31.
Potassium's electron configuration is [Ne] 4s¹ and Gallium's electron configurations is [Ne] 4s²3d¹⁰4p¹. Since both are in Period 4, they have the same number of core e⁻. Therefore, the shielding effect is the same.
However, since Gallium is element 31, it has 31 protons compared to Potassium, which is element 19 and has 19 protons. Gallium would have a greater Zeff than Potassium as it has more protons. Therefore, the FOA between the electrons and nucleus of Ga is much stronger than that of K. Thus, Ga requires more energy to overcome those FOA to remove the 4p¹ e⁻. Since K has less protons, it will have a smaller Zeff and thus less FOA between the e⁻ and nucleus, requiring less energy to remove the 4s¹ e⁻.
A train station in Tokyo uses tiles that convert people’s footsteps into electricity.
A.Restore
B. Rethink
C. Reduce
D. reuse
Answer:
reuse
Explanation:
H2 (g) + F2 (g) ----- > HF(g) *
What type of reaction?
Answer: Hydrogen fluoride
Explanation:
whats the mass of neon
Answer:
20.17 (or if you want to round .18)
Explanation:
If you ever need help with this again the atomic mass is the number underneath the element name
Electromagnetic waves will travel the SAME SPEED (speed of light) WITHIN a medium as it does WITHOUT a medium. Question options: True False
Answer:
True
Explanation:
The speed that electromagnetic waves will travel within any medium is the same as those without a medium. The speed of electromagnetic wave is a constant and does not depend on the material of the medium.
Electromagnetic waves are waves that do not require a material medium for their propagation. They are able to pass through vacuums and mediums with particles at constant speed. It is mechanical waves whose speed is medium dependent. Mechanical waves have varying speed based on the mediums they move through.identify the molar mass of na2(so4)3
Answer:
142.04 g/mol is the answer to your question.
How many electrons are transferred in total in this
reaction?
2 NH3 + 2 O2 – N2O + 3 H2O
4 electrons
10 electrons
8 electrons
6 electrons
Answer:
10.
....................
.......
Which things are larger than cells? Put an X next to (or highlight) the things that are generally larger than a typical animal or plant cell.
_____thickness of a leaf ____grain of salt
_____atom _____protein molecule
_____width of hair x DNA
_____piece of sawdust _____eye of an ant
_____Water molecule _____tiny seed
_____bread crumb _____larva of a tiny fruit fly
_____bacteria _____period at end of sentence _____ virus
_____speck of pepper _____chromosome _____ frog embryo _____dust mite _____point of a pin _____ flea egg
Answer:
Explanation:
x thickness of a leaf x grain of salt
_____atom _____protein molecule
x width of hair x DNA
x piece of sawdust x eye of an ant
_____Water molecule x tiny seed
x bread crumb x larva of a tiny fruit fly
x bacteria x period at end of sentence _____ virus
x speck of pepper _____chromosome x frog embryo x dust mite xpoint of a pin x flea egg
The final temperature and pressure in a container is 234K at 210 kPa.
If initial temperature was 175 K, what was the starting pressure?
Answer:
Initial pressure = 157 kpa (Approx)
Explanation:
Given:
final temperature = 234 K
final pressure = 210 kpa
Initial temperature = 175 K
Find:
Initial pressure
Computation:
Initial pressure / Initial temperature = final pressure / final temperature
Initial pressure / 175 = 210 / 234
Initial pressure = 157 kpa (Approx)