Answer:
A. cutting a substance into four pieces
Explanation:
The others include burning, reacting, and rust which make up a chemical change.
Cutting a substance into four pieces indicates a physical change. The correct option is A.
What is physical change?Even before to and after a physical change, the material implicated is unique architectural the same.
Physical changes include texture, shape, heat, and the beginning of a change in the state of matter. The texture of a substance influences how it feels.
A physical change is simply a change in appearance. The situation has not changed since the change.
Physical change can be seen in the use of cutting paper, melting butter, dissolving salt in water, and breaking glass.
Chemical reaction takes place when bonds among molecules or atoms are broken or formed.
This implies that one material with a specific set of properties is transformed into another substance with a different set of properties.
Thus, the correct option is A.
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help please lol I’m stuggling
Answer:
balenced
Explanation:
Combustion of a hydrocarbon, X, is given by the equation: 2 X + 5 O2 (g) --> 4 CO2 (g) + 6 H2O (g) ∆H = -75.0 kJ Use this information and the standard enthalpies of formation listed in the text or elsewhere, to determine the standard enthalpy of formation of the hydrocarbon, X.
Answer:
Hof(X) = - 1474.9 KJ/mol
Explanation:
The reaction equation given to us is:
2 X + 5 O2 (g) --> 4 CO2 (g) + 6 H2O (g) ∆H = -75.0 kJ
Now, the equation for the standard enthalpy of formation of the reaction is written as follows:
ΔH = 4*Hof(CO2(g)) + 6*Hof(H2O(g)) - 2*Hof(X) - 5*Hof(O2(g))
where,
ΔH = - 75 KJ
Hof(CO2(g)) = Standard Heat of Formation of CO2(g) = -393.5 KJ/mol
Hof(H2O(g)) = Standard Heat of Formation of H2O(g) = -241.8 KJ/mol
Hof(X) = Standard Heat of Formation of X = ?
Hof(O2(g)) = Standard Heat of Formation of O2(g) = 0 KJ/mol
Therefore,
-75 KJ = (4)(-393.5 KJ/mol)+ (6)(-241.8 KJ/mol) - (2)(Hof (X)) - (5)(0 KJ/mol)
- 75 KJ + 3024.8 KJ = - (2)(Hof(X))
Hof(X) = -2949.8 KJ/2 mol
Hof(X) = - 1474.9 KJ/mol
PLEASE HELP I NEED HELP ASAP I WILL GIVE BRAINLIEST AS SOON AS POSSIBLE
Answer:
1 . 2.393e+ 9
2. ???
3. 3.25e-6
Explanation:
2393 kg = 2.393e+9 mg
43.23 g = 4.323 dam
0.325 cm = 3.25e-6 km
(Note: I'm not 100% that these are correct, but I hope this helps you tho. ^^)
Which of the following forces weathers objects by expanding and changing shape?
Moving water
Wind
Plants
Ice
A given sample of oxygen occupies 500 mL when the pressure is 800 mmHg. What volume will the gas occupy at 200 mmHg, provided the temperature remains constant?
Answer:
The volume of the gas at 200 mmHg will be 2 L.
Explanation:
As the volume increases, the gas particles (atoms or molecules) take longer to reach the walls of the container and therefore collide with them fewer times per unit of time. This means that the pressure will be lower because it represents the frequency of collisions of the gas against the walls. In this way pressure and volume are related, determining Boyle's law which says:
"The volume occupied by a certain gaseous mass at constant temperature is inversely proportional to pressure"
Boyle's law is expressed mathematically as:
P * V = k
Now it is possible to assume that you have a certain volume of gas V1 that is at a pressure P1 at the beginning of the experiment. If you vary the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1 * V1 = P2 * V2
In this case:
P1= 800 mmHgV1= 500 mLP2= 200 mmHgV2= ?Replacing:
800 mmHg* 500 mL= 200 mmHg* V2
Solving:
[tex]V2=\frac{800 mmHg* 500 mL}{200 mmHg}[/tex]
V2= 2,000 mL= 2 L (being 1,000 mL=1 L)
The volume of the gas at 200 mmHg will be 2 L.
One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish's weight is recorded daily. All tanks were of the same size and shape. IV: DV: Control Group:
The question is incomplete, the complete question is;
One tank of goldfish is feed the normal amount which is once a day, a second tank is fed twice a day, and a third tank is fed four times a day during a 6 week study. The fishes' body fat is recorded daily.
Independent Variable-
Dependent Variable-
Constants
Control Group-
Answer:
A) The amount of food the gold fish receives
B) Body fat of the gold fish
C) -Type of fish used in the study (gold fish)
Time period within which the fishes were fed (Six week period)
Shape and size of tank
D) group of gold fish fed the normal amount
Explanation:
The purpose of the study is to determined the impact of amount of feed on the body fat of gold fish. Hence, the amount of feed is the independent variable while the body fat of the feed is the dependent variable.
The control group receives the normal amount of feed (once a day). The fishes are all gold fish, fed within a six week period. All the tanks were of the same shape and size. These are the constants in the study.
what kind of bond is between a halogen and an alkali metal
At what time of day is sunlight strongest - in the early morning (when the Sun has just risen)
or at noon (when the Sun reaches its highest point)?
Answer:
noon is the answer. Hope it helps
Answer:
Noon
Explanation:
Hope this helps <3
The equation 1/2 N2 + 3/2 H2+ NH3 is not appropriately written because
Answer:
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True or False?
To increase acceleration of a object, you reduce its mass or increase the applied force.
the only nonmetal in group 1
Answer:
Hydrogen
Explanation:
Hydrogen is the only non metal in group on of the period table of elements.
HELP ASAP!! FILL IN THE BLANKS! will be brainliest!!!
Answer:
Don't mark me brainliest because of this but I'm pretty sure your supposed to give us the words because teachers don't give you things like that without the words you will the answer in with.
Answer:
Same as number of NUETRONS
POSITIVE charge
number of protons is the same as the atomic NUMBER
Located in the Nucleus
Larger mass than ELECTRONS
Explanation:
GOOD LUCK
what dose pH mean on the periodic table
Which postulate of Dalton’s atomic theory has not been disproved by further investigation?
A. All matter is made of tiny particles called atoms.
B. Atoms are indivisible and indestructible.
C. All atoms of a given element have the same mass.
D. Atoms of an element are all identical.
Answer:
The indivisibility of an atom was proved wrong: an atom can be further subdivided into protons, neutrons and electrons...
hope this helps u
The Daltons atomic model gave the theory of chemical combination and the law of conservation of atoms. All matter is made of atoms is not disapproved. Thus, option A is correct.
What was Dalton’s atomic theory?Dalton’s atomic theory was given by John Dalton and involved several main points. According to the theory that matter has been composed of tiny atoms that are indestructible and indivisible.
It also stated about the mass, as atoms of various elements have different masses and the properties are shared by the atoms of the same element only. It gave rise to the law of conservation of mass, definite, and multiple proportions.
One of the laws is about matter being made of tiny particles called atoms. It has been not disproved by further investigation in any of the atomic models and theories.
Therefore, option A. the matter is made of atoms is not disproved.
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What is a substance said to be if it evaporates easily?
A.crystallized
B.condensing
C.changing pigmentation
D.volatile
Metals typically lose electrons and become cations lose electrons and become cations lose electrons and become anions lose electrons and become anions gain electrons and become anions gain electrons and become anions gain electrons and become cations
Answer:
Metals typically loose electrons and become cations
Explanation:
Metals are typically found towards the left hand side of the periodic table. They typically possess fewer electrons in their outermost shell compared to nonmetals.
As a result of this, when metals form chemical bonds with other elements, it is energetically more favourable for metals to loose electrons and form cations.
Help please 2 mins til it submits
two atoms are isotopes of the same element, the atoms must have
Answer:
the answer is isotopes
I hope this will help you
The sphere was dropped into water in a graduated cylinder as shown below
Answer:65 ML
Explanation:
Elements in the same _____ on the periodic table have the same number of valence electrons.
How many elements are present in the compound?
Mg2As3COHNi2
Answer: 6
Explanation: none needed lol
Pleaseee help me on this
PLEASE HELP ASAP!!
If an element has the atomic number of 13 and a mass number of 27, what
is that element?
-cobalt
-aluminum
-silicon
what determines the atomic number of the atom
Answer:
the number of protons
Explanation:
that's it
Which element has the most metallic characteristics?
O Selenium (Se)
Arsenic (As)
O Germanium (Ge)
O Gallium (Ga)
Answer:
(Ge)
Explanation:
I'm just taking a wild guess really!
The amount of matter in an object is its ____
weight
mass
volume
density
PLEASEEE HELPPP!!!! AND EXPLAIN PLS
Answer: True?
Explanation: THere is no question but I do know that is true because I answers that on a test and got it right. It was asking about:
how many Helium and oxygen molecules = H2O = + O2
which factor affects an objects weight but not its mass?
A. Volume
B.Magnetism
C. Gravity
D Conductivity
Answer:
Gravity
Explanation:
Gravity is the pull of an object to another object like a human to the Earth. This is weight.
Answer:
C. Gravity
Explanation:
Just Took The Test And Got A Perfect Score. ;)
which of the following pairs would have
a the
larger size
K or k+ ?
Explain your
ur answer.
Answer: Here u go!
Explanation:
In other words, "K"^(+) has bigger effective nuclear charge than "Cl"^(-), which translates to a bigger net positive charge felt by the outermost electrons. This will compress the energy levels a bit and make the ionic radius smaller for the potassium cation. Therefore, the chloride anion will have the larger atomic radius.
Hope this helps ma dude!
1) Equal masses of different substances have the same volumes.
Answer:
True
Explanation: