If you do not recall the exact date of an event, it is okay to use a general time reference instead.
Please select the best answer from the choices provided
T
F
Answer:
True
Explanation:
Sorry if this is late lol
Answer:
The answer is True.
Explanation:
Did not copy
Why is it important o differentiate between human and animal blood from a crime scene? A) To determine whether an animal might have been injured. B) In order to accurately identify the source of any blood. In order to thoroughly and accurately recreate the crime scene. D To determine the possible source of any trace evidence such as hair or bite marks
Answer:
B) In order to accurately identify the source of any blood. In order to thoroughly and accurately recreate the crime scene.
A 10.151 g sample of window cleaner containing ammonia was diluted with 39.466 mL of water. Then 4.373 g of solution was titrated with 14.22 mL of 0.1063 M HCl to reach a bromocresol green end point. Find the weight percent of NH3 (FM 17.031) in the cleaner.
Answer:
2.878 (w/w)%
Explanation:
The reaction of NH3 with HCl is:
NH3 + HCl → NH4Cl
That means 1 mole of ammonia reacts per mole of HCl. The moles of HCl that reacts = Moles of ammonia are:
14.22mL = 0.01422L * (0.1063mol HCl / L) = 0.001512 moles HCl = Moles ammonia
In mass:
0.001512 moles NH3 * (17.031g / mol) = 0.02574g of NH3 in the solution.
The concentration in weight percent of the diluted solution is:
0.02574g of NH3 / 4.373g * 100 = 0.5887 (w/w)%
This is the concentration of the diluted solution that was diluted from 10.151g to 10.151g + 39.466g = 49.617g
-Assuming density of water = 1g/mL-
The solution was diluted:
49.617g / 10.151g = 4.888 times.
That means the concentration of NH3 in the original cleaner is:
0.5887 (w/w)% * 4.888 =
2.878 (w/w)%How many electrons does 2Na+1 have
Answer:
So... for the element of SODIUM, you already know that the atomic number tells you the number of electrons. That means there are 11 electrons in a sodium atom. Looking at the picture, you can see there are two electrons in shell one, eight in shell two, and only one in shell three.
Explanation:
brainliest pleaseeee <3
Answer:
so there would be 2 electrons because
Explanation:
sodium has 11 electrons but if you look at the shels it onl has one electron (from the image im looking at) and the other shell only have one so theres 2 electrons
. Which of these is an example of a scientific observation? *
AThe rock is smooth and gray."
BWhat is the best brand of soap?"
CMost people drive black cars."
DThe sun's light helps plants grow."
Answer:
D. The sun's light helps plants grow
Explanation:
This is a scientific observation, because it is describing the structure of a living thing.
Pure H2oboils at 100 ˚C and freezes at 0 ˚C. What is the melting point and boiling point of water
after the addition of potassium chloride
Answer:
Recall the colligative properties of freezing point depression and boiling point elevation.
In proportion to the molality product of the solute, (
i
m
), the boiling point will raise and the freezing point will decrease.
Now, consider tap water. You know this!
Is tap water pure water? Of course not! It's a solution of many ions of metals or other inorganic compounds.
Hence, it has a varied boiling and melting point, by definition.
Explanation:
The colligative properties like the boiling point elevation and freezing point depression depend on the solute concentration. The boiling point of the water will increase while the freezing point will decrease.
What are colligative properties?Colligative properties are the attributes that depend on the amount or the solute concentration rather than on the type or identity of the solute particle. They include freezing point depression, lowering of vapor pressure, osmotic pressure, and boiling point elevation.
The boiling point elevation is the increase of the solvent's boiling point by the addition of the solute. Potassium chloride is a salt and a non-volatile solute that increases the boiling point of the solution.
The freezing point depression is one of the colligative properties that states the direct relationship between the molality and the freezing point of the solvent. As potassium chloride is a non-volatile solute it decreases the freezing point of the substance.
Therefore, the boiling point will increase but the freezing point will decrease after the addition of potassium chloride.
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Which of the following best describes the change in Antarctic temperature from about 440,000 years ago to about 340,000 years ago?
A
The temperature increases by about 10 S
B
The temperature decreases by about 8°C.
С
The temperature increases by about 12°C and then decreases by about 12°C.
D
The temperature decreases by about 10°C and then increases by about 12°C.
Answer: С . The temperature increases by about 12°C and then decreases by about 12°C.
Explanation:
Temperatures around the world have been on the rise since the Industrial revolution as humans clog the planet with Carbon Dioxide and other pollutants. This had led to a rise in temperatures that has seen ice levels fall and sea levels rise around the world.
Temperature fluctuations on the other hand are not a new thing. Studies show that in Antarctica temperatures from about 440,000 years ago to about 340,000 years ago increased by 12°C and then decreased by about 12°C.
Answer:
C. The temperature increases by about 12°C and then decreases by about 12°C.
Explanation:
The attached shows ice core data that indicates the time period of interest was about the period of one full cycle of climate change. Temperature went up, then went down again to about its original level. The range of change was on the order of 12 °C.
Which carboxylic acid can be combined with an alcohol to form the ester shown below?
Answer:
CH₃CH₂CH₂COOH.
Explanation:
To know which option is correct, let us hydrolysed the given ester. This is illustrated in the attached photo.
Hydrolysis of ester involves breaking the ester bond by a water molecule to produce the corresponding alcohol and carboxylic acid.
From the reaction given in the attached photo, we can see that the carboxylic acid needed to produce the desired ester is butanoic acid, CH₃CH₂CH₂COOH.
If the titration of 0.8094 g of 100% pure
KHP requires 40.25 mL of NaOH, what
is the concentration of the NaOH
solution? Remember KHP is potassium
hydrogen phthalate, KHC2H4O4. Show
this calculation in your lab notebook.
Answer:
Explanation:
molecular weight of potassium hydrogen phthalate = 204
.8094 g of KHP = .8094 / 204 = 3.967 x 10⁻³ moles
3.967 x 10⁻³ moles of KHP must have reacted with 3.967 x 10⁻³ moles of NaOH
concentration of NaOH = 3.967 x 10⁻³ / 40.25 x 10⁻³
= .098 M .
The value of AE for a system that performs 127 kJ of work on its surroundings and gains 59 kJ of heat is
kJ.
a 68
b -68
c 7493
d -186
e 186
as a change of state takes place, heat and temperature
a. increase stays the same
b. stays the same, stays the same
c.stays the same, changes.
d.increases,increases
Answer:
c. stays the same, changes
Explanation:
temperature and heat go hand in hand, however while the change of state occurs, the temperature remains the same while the heat increases since the heat input is constant.
As a change of state takes place, heat and temperature: C. stays the same, changes.
Matter can be defined as anything that has mass and occupies space. Thus, any physical object or substance that is found on earth is typically composed of matter.
Since all matter are made up of atoms, they have a property of existing in three (3) distinct states and these include;
Solid.Gas.Liquid.Generally, matter changes state when heat (thermal energy) is released or absorbed with a corresponding change in its temperature.
In conclusion, at the point when the change of state is taking place, heat stays the same and temperature changes.
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In models of molecules, spheres of different colors and
sizes represent different types of atoms.
Which model shows a molecule of a substance that is made up of three
elements?
A
B
C
Or
D ?
Answer:
D
Explanation:
According to this question, each model of molecules in the options contains spheres of different colors and sizes representing different types of atoms. The atoms of the same element are the spheres of same color and size while atoms of different element are of different color or size.
Therefore, the model showing a molecule of a substance that is made up of three elements is model D because it is made up of three distinct spheres representing atoms of each element.
- The red sphere is the atom of the first element
- The big dark sphere is the atom of the second element
- The small white sphere is the atom of the third element
Answer:
D
Explanation:
Lars observes a substance to be a solid and to float in water at room temperature (23°C). Based on the given properties, which substance is the most likely identity of this sample?
Substance Melting Point (°C) Boiling Point (°C) Density at Room Temperature (g/cm3)
carbon tetrachloride -22.9 76.7 1.59
cetyl alcohol 49.3 344 0.811
dichlorobenzene 53.5 174 1.25
sulfur hexafluoride -64 -50.8 0.00617
A.
carbon tetrachloride
B.
cetyl alcohol
C.
dichlorobenzene
D.
sulfur hexafluoride
Answer:D. Sulfur Hexafluride
Explanation:
D. Sulfur Hexafluride
Explanation:
above it says the substance floats above water at room temperature and lists some substances and their density at room temp!
we know that the density of water is 1.0 so the substance in order for it to float has to be less than 1.0 and the densities for Sulfer Hexa, are all less than 1!!
“An icy wind teetered trash cans and turned my cheeks to marble.”
What does the imagery in this sentence tell the reader about the weather?
in seedfolks
Pls help I dont get science so pls help me
FILL IN THE BLANKS ASAP 40 POINTS AND BRAINLIST
Answer:
1.) land
2.) water
3.) warmer
4.) rises
5.) sea
Explanation:
Hot air rises, and land heats up first.
Answer:
Here are the answers:
1.) land
2.) water
3.) warmer
4.) rises
5.) sea
Explanation:
During a day at the beach, the land heats up faster than the water. Because of this, the air over land rises over the land and the cooler, more dense air, blows into the ocean, creating a sea breeze.
What’s it called when a sound wave is slowed down by a new medium?
Answer:
Refraction of waves involves a change in the direction of waves as they pass from one medium to another. ... Sound waves travel slower in cooler air than they do in warmer air.
Explanation:
Which is the larger atom S or Mg
Answer:
Mg
Explanation:
If one were comparing just the neutral atoms Mg and S, the S atom would be smaller as both elements are in the same period and sulfur is more to the right
Complete each statement by choosing the correct answer from the drop-down menu.
are the types of muscle tissue found in the human body.
Muscle cells are specialized to
are the two specialized proteins found in muscle.Muscle Tissue
Answer:
smooth, skeletal, cardiac
contract
actin and myosin
Explanation:
edge
Answer:
The correct answers are
smooth, skeletal, cardiac
contract
actin and myosin
Convert 3564 to Scientific Notation:
*
Answer:
3564 = 3.564 x 10^3
Explanation:
i.e expresing the value in standard form.
How for way is the Neptune from the sun
The human eye cannot see anything less than 40 micrometers in size. What is this length in meters?
Answer:
0.00004
Explanation:
i dont have one its just i know
The lowest energy state of an atom is its
A. Highest-occupied energy level.
B. Principle quantum number.
C. Electron configuration.
D. Ground state.
Answer:
Principle quantum number.
Explanation:
Why does a small pebble sink in water?
A small pebble sinks in water because its density is greater than the density of water. Density is a measure of how much mass is packed into a given volume. If an object is denser than the liquid it is placed in, it will sink.
When a pebble is dropped into water, the water exerts an upward force called buoyancy. This force opposes the weight of the pebble, and if the pebble is less dense than water, it will experience an upward force greater than its weight and float.
However, if the pebble's density is greater than that of water, the downward force due to its weight will be greater than the upward buoyant force, causing it to sink.
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What would be the temperature as well as pressure inside and outside of a can if it were to be placed in cold water?
Answer:
The hot gas molecules are the same pressure as the air outside the can. When the can is placed in cold water upside down, the hot gas water molecules are cooled very rapidly. ... Since the air pressure outside the can is stronger than that inside the can, it causes the can to collapse.
Explanation:
I will mark brainliest as soon as there are two answers! Please be quick, I'm timed
A mineral forms in water heated by magma inside Earth.
Which statement best describes this mineral?
The mineral formed through evaporation.
The mineral crystallized from molten material.
The mineral formed when a hot water solution cooled.
The mineral likely has all the same properties as the surrounding rock.
Answer: i would do the mineral formed when a hot water solution cooled because you said that a mineral forms in water heated by magma inside Earth.
Explanation:
The answer would be C
Explanation:
When magma cools down it will change into a rock type so the answer would be C.
How many grams of F are in 225 g CaF2?
Answer:
109.575
Explanation:
3.) Why is argon (Ar) larger than neon (Ne)?
Answer: Here u go!
Explanation:
The electron cloud of argon is thus larger and more polarized, able able to express mawr inter molecular forces Vander Waals forces, which results in a higher boiling point due to these increase forces. Due to this, the boiling point of argon is higher are gone. We can see its boiling point is 87.2 Kelvin's, whereas a neon and spoiling point is 24.5.
Hope this helps!
Explanation:
Argon has an atomic number of 18, while neon has an atomic number of 10.
The atomic radius is comprised of the atom’s nucleus and electron cloud. As you go down on the periodic table, the effective nuclear charge decreases. This results in more screening of the electrons
from the nucleus (decreasing the attraction between the nucleus and the electrons) resulting in a larger atomic radius.
However, because they’re both noble gasses, the size difference in this case can be easier described by the number of particles in each atom.
Argon has 18 protons, 18 electrons and 22 neutrons.
Neon has 10 protons, 10 electrons and 10 neutrons.As you can see, argon has more “stuff.”
The increase in protons and electrons in particular results in a larger electron cloud, which means a much larger atomic radius than in neon.
i hope it helps u :)
Which statement describes an intensive property of matter?
Answer:
hope it helped you.
Explanation:
The properties of matter that do not depend on the size or quantity of matter in any way are referred to as an intensive property of matter. Temperatures, density, color, melting and boiling point, etc., all are intensive property as they will not change with a change in size or quantity of matter.
Order these chemical species by increasing of an aqueous solution of each. That is, imagine making an solution of each species. Select next to the species that makes the solution with the lowest . Select next to the species that makes the solution with the next higher , and so on. Notice that some of the rankings have been filled in for you already. Also notice that water is on the list. For that particular case, just compare the of pure water to the of the other solutions.
Species Relative PH of 0.1M aqueous solution
HCOOH
CIO2^-
HCOO^-
H2O
H3PO4
H2PO4
H2PO4^-
H3O^-
HClO2
Answer:
H3O^+ < HClO2 < H3PO4< HCOOH < H2PO4^-<CIO2^-<H2O< HCOO^-
Explanation:
The pH of a solution refers to the negative logarithm of it's hydrogen ion concentration. Generally, the hydrogen ion concentration of an acid is always greater than that of its conjugate base. Hence, the conjugate acid always has a lower pH than the conjugate base.
This can be seen in the species, H3O^+ and H2O, HClO2 and ClO2^- etc.