Answer: chemical change
Explanation:
A physical change occurs when a substance changes phase. For example, boiling pure water (H₂O) is physical change of substance (from liquid to gaseous state).
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!!
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
How for way is the Neptune from the sun
Velocity is
is a given
O distance, time
O speed, displacement
O speed, direction
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
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.
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
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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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 .
A pizza is an example of a heterogeneous mixture. Explain why it is classified as such?
Answer:
Hi!
So, a homogeneous mixture is when the parts that make up the mixture are all mixed in perfectly evenly, so they're only appearing as one uniform substance.
In a heterogeneous mixture, the pieces are not evenly mixed. A pizza has separate parts, like the crust and toppings, so it's a heterogeneous mixture.
Chemical properties can be observed without changing the substance
Answer:
chemical properties can only be measured only by changing a substance chemical identity
Explanation:
apex
Pls help I dont get science so pls help me
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
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
“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
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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Who would most likely be required to work with sodium hydroxide?
a plumber
a gardener
a bricklayer
a mechanic
Answer:
i think plumber
Sodium hydroxide is generally referred to as caustic soda used in soaps and cleaners. A plumber would most likely be required to work with sodium hydroxide. Hence, option A is correct.
What is the use of sodium hydroxide?
Soaps, paper, explosives, dyes, and petroleum are all made with sodium hydroxide. The presence of sodium hydroxide in a cleanser or a homemade aqueous solution converts these disconcerting fats into soaps, which are easily removed by water.
They have no odor and no color making them react with water and strong acids to produce salts. They are considered ionic compounds with sodium cation and chloride anion. They also are used in oxide coating and cleaning of metals.
Therefore, option A. plumber will most likely use sodium hydroxide.
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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:
When all colors of light are absorbed, what do you see?
Black
Orange
Pink
Yellow
Answer:
Black
Explanation:
hope it helps
have a nice time ..,
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.
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.
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 of the following is true for polar jet streams?
They bring cool air.
They bring warm air.
They blow at the equator.
They blow from north to south.
Answer:
A: They bring cool air.
Explanation:
Took the test and got it correct. :)
Jet streams are fast flowing meandering air currents. Polar jet streams bring cool air through the atmosphere. Polar jets meet subtropical jets at some regions.
What are polar jet streams ?The polar jet stream, which travels through the lower layers of the atmosphere in the Northern Hemisphere, is a swiftly moving band of westerly winds.
The confluence of warm air ascending from the tropics and cold air masses descending from the arctic produces the jet. The denser cold air lowers and deflects the warmer air areas north, creating deep troughs and steep ridges that give the jet stream its wavy appearance.
As pockets of cold air intermittently sneak down from the Arctic, this pattern spreads across the mid-latitudes of North America, Europe, and Asia, producing opposing waves and flows that speed eastward due to the earth's rotation.
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Which statement accurately describes the atoms of a specific element? *
An indium, In, atom contains 115 protons inside the nucleus and 49 neutrons outside the nucleus.
A scandium, Sc, atom contains 45 electrons outside the nucleus and 21 neutrons inside the nucleus.
An aluminum, Al, contains 27 electrons and 27 protons inside the nucleus.
A zinc, Zn, atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus
Answer:
the last one, (A zinc, Zn, atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus)
A zinc, Zn, atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus accurately describes the atoms of a specific element ,therefore option (d) is correct.
What are the characteristics of zinc element ?Zinc is placed in group 12 of the periodic table. It is in the first period of transition or d block elements, and fourth period of the periodic table.
Zinc is a metal. It has two valence electrons that are lost easily. Zinc forms positive ions with 2+ charges, like the metals of the alkaline earth family.
Uses of zinc element -:
Zinc is an important trace element for human beings. Zinc is used for making brass, an alloy of copper and zinc.Zinc is used as the anode in dry cells.A zinc, Zn, atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus accurately describes the atoms of a specific element ,hence option (d) is correct.
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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:
A student titrates 0.1719 g of an unknown monoprotic acid to the equivalence point with 21.85 mL of 0.1062 M NaOH. Which of the following is most likely to be the unknown acid? propionic acid (MM 74.08 g/mol) nitrous acid (MM 47.01 g/mol) chlorous acid (MM 68.46 g/mol) benzoic acid (MM 122.12 g/mol) lactic acid (MM: 90,08 gimol)
Answer:
Propionic acid
Explanation:
Step 1: Write the generic neutralization reaction
HA + NaOH ⇒ NaA + H₂O
Step 2: Calculate the reacting moles of NaOH
21.85 mL of 0.1062 M NaOH react.
0.02185 L × (0.1062 mol/L) = 2.320 × 10⁻³ mol
Step 3: Calculate the reacting moles of HA
The molar ratio of HA to NaOH is 1:1. The moles of HA are 1/1 × 2.320 × 10⁻³ mol = 2.320 × 10⁻³ mol.
Step 4: Calculate the molar mass of HA
0.1719 g of HA correspond to 2.320 × 10⁻³ moles.
MM = 0.1719 g/2.320 × 10⁻³ mol = 74.09 g/mol
With this molar mass, the most likely acid is propionic acid.
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.
Convert 3564 to Scientific Notation:
*
Answer:
3564 = 3.564 x 10^3
Explanation:
i.e expresing the value in standard form.
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:
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.