Which of the following is a chemical change?
melting of ice
burning of wood
breaking of glass
Evaporation of water
Answer:
The answer is burning of wood
Explanation:
just took the quiz
The chemical formula for water is h2o. According to this formula what is the composition of a water molecule
Answer:
two hydrogen atoms and one oxygen atom
Explanation:
What type of reaction is
Mg + CI -> MgCI2?
A. Double-replacement
B. Synthesis
C. Single-replacement
D. Decomposition
Try it
Which statements accurately describe volume? Check all that apply.
Explanation:
what is the question jjsjmwujjduwhfjd
Answer:
Volume is a physical property of an object
One unit of volume is the milliliter
Liquids and solids have constant volumes
Explanation:
When we look at the periodic table of elements, the elements in a have the same number of valence electrons
2. When the vapor pressure of water is 80 kpa the temperature of the
water is:
O 93 °C
O 103 °C
O 60°C
None of above
Answer:
103
Explanation:
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If you have 1.2754x1020 molecules of Barium nitrate (Ba(NO3)2), how many moles of barium nitrate do you have?
Answer: ??? moles Ba(NO3)2 (round to 5 sig figs)
Answer:
0.00021186 moles of barium nitrate
Explanation:
The given parameter is as follows;
The number of molecules of Barium nitrate Ba(NO₃)₂ = 1.2754 × 10²⁰ molecules
The number of molecule present per mole of Barium nitrate, is given by Avogadro's number, 6.02 × 10²³
1 mole of a substance contains 6.02 × 10²³ molecules
The umber of moles in a substance = (The number of molecules of the substance)/(The number of molecules per mole)
Therefore the number of moles of barium nitrate in 1.2754 × 10²⁰ molecules of barium nitrate = (1.2754 × 10²⁰)/(6.02 × 10²³) ≈ 0.00021186 moles (rounding to 5 significant figures)
The number of moles of barium nitrate present in 1.2754 × 10²⁰ molecules of barium nitrate ≈ 0.00021186 moles
a car starts from rest gains velocity 20m/s in 10 second find its acceleration?
Answer:
acceleration(a)=2m/s²
Explanation:
initial velocity(u)=0m/s
final velocity (v)=20m/s
time taken (t)=10sec
now
v=u+at
20=0+a*10
a=2m/s²
If you have 0.95 moles of FeCl3, how many moles of MgCl2 do you produce in the reaction
FeCl3 + Mg --> MgCl2 + Fe?
I REALLY NEED HELP PLEASEEEEE
What makes up a film badge?
an electrolyte paste spread across a plastic sheet
a thin film of salts and other chemicals on clear acetate
layers of photographic film covered in black paper
a panel of photographic film exposed to the air
Answer:
Question:-What makes up a film badge?
Answer:-a panel of photographic film exposed to the air
Why is fingerprint identification considered a science?
Answer:
Forensic scientists have used fingerprints in criminal investigations as a means of identification for centuries. Fingerprint identification is one of the most important criminal investigation tools due to two features: their persistence and their uniqueness. A person's fingerprints do not change over time.
Explanation:
can someone pls help me with this!
Answer:
weathered rock and deceomposed material
Explanation:
What is a radical?????
Answer:
radical dudes
Explanation:
Answer:
relating to or affecting the fundamental nature of something; far-reaching or thorough.
Explanation:
When determining molecular polarity, which scenario is not possible:
A A polar molecule with polar bonds
B A nonpolar molecule with polar bonds
с A polar molecule with nonpolar bonds
D A nonpolar molecule with nonpolar bonds
Answer: Option C is correct
A polar molecule with nonpolar bonds
Explanation:
A polar molecule with nonpolar bonds cannot be polar because a polar molecule has net dipole that it has one end slightly positive and the other end slightly negative which allows the distribution of atoms .
Therefore it cannot have non polar bonds because non polar bonds allow electrons to be shared equally and it take place between non elemental substances or substances that are not elements , it cannot occur in elemental substances because these substances have different electronegativities which can be held by polar bonds alone.
Answer:
The correct answer is C. A polar molecule with nonpolar bonds
Explanation:
Polarity is the property of a molecule of having a dipole moment. Based on this, a molecule can be polar -with dipole moment- o nonpolar. The polarity of a molecule is determined by:
- the presence of elements with differences in electronegativity which results in polar bonds.
- geometry of the molecule
Polar bonds are vectors and if they are opposite (equal in magnitude with opposite direction) so they are cancelled out. A polar molecule must have polar bonds, buy they can be cancelled out by opposite positions in the molecule geometry. For example, CO₂ (carbon dioxide) has polar bonds C-O because they are composed by elements with different electronegativities, but the molecule is linear so the two bonds C-O are cancelled out and the molecule is nonpolar.
Therefore, from the options, the only non possible scenario is C - a polar molecule with nonpolar bonds - because polar molecules always have polar bonds. The opposite situation can be true: a non polar molecule wiith polar bonds as we saw in the example of CO₂.
When Iodine-131 emits a β particle (beta particle), what nuclide is produced? *
When Iodine-131 emits a β particle will produce Xe-131
Further explanationRadioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles ₀γ⁰ positron particles ₁e⁰ neutron ₀n¹So for reaction Iodine-131 :
[tex]\tt _{53}^{131}I\rightarrow _{-1}^0\beta +_{54}^{131}Xe[/tex]
Question, Answer, and Explanation are within the picture of files:
most neutral atoms of argon have an atomic mass of 40 amu and an atomic number of 18. what are these atoms composed of?
A.18 protons,22 neutrons, and 22 electrons
B.18 protons 22 neutrons 18 electrons
C.18 protons 18 neutrons 18 electrons
D,18 protons 40 neutrons and 18 electrons
Answer:
B.18 protons 22 neutrons 18 electrons
Explanation:
Neutral atom of Argon;
Atomic mass = 40amu
Atomic number = 18
Let us find the number of the subatomic particles;
Protons are the positively charged particles in an atom
Electrons are the negatively charged particles
Neutrons do not carry any charges.
Now;
Atomic mass = number of protons + number of neutrons
Atomic number = number of protons
number of protons = 18
In a neutral atom, number of protons equals number of electrons
number of electrons = 18
Number of neutrons = atomic mass - atomic number
Number of neutrons = 40 - 18 = 22
18 protons, 18 electrons and 22 neutrons
Which phrase best describes bronze?
a copper–tin alloy
an ionic compound of copper and tin
a pure metal
a mineral ore containing copper and tin
Answer:
a mineral ore containing copper and tin
Answer:
Copper-tin alloy
Explanation:
just took the test :D
chemically stable than they would
14. The atoms in a water molecule are
be as individual atoms.
A Less
B. More
C. Similarly
D. Not
Answer:C
Explanation:
Question 5 of 5
Carbon has six protons. Which model shows a neutral atom of carbon?
Answer:
its d
Explanation:
Model D shows a neutral atom of carbon as it has 6 protons in the nucleus and 6 electrons in it's orbits.
What is an atom?
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
Learn more about atom,here:
https://brainly.com/question/13654549
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What is the energy of a photon having a wavelength of 2.60 ✕ 10-8 m?
J
The energy of a photon : 7.645 x 10⁻³⁴ J
Further explanationRadiation energy is absorbed by photons
The energy in one photon can be formulated as
[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ , Hz
c = speed of light
= 3.10⁸ m/s
λ = wavelength ,m
wavelength λ of 2.60 ✕ 10⁻⁸ m
The energy :
[tex]\tt E=h.\dfrac{c}{\lambda}\\\\E=6.626.10^{-34}\times \dfrac{3\times 10^8}{2.6\times 10^{-8}}\\\\E=7.645\times 10^{-34}~J[/tex]
HELP ME with THIS I am time i have a little bit of time and still have more questions !!! CHEMISTRY!!
Answer:
1. is B 2. is C or B
Explanation:
How is the crust and the inner core alike
Answer:
They are both solids
Explanation:
I had to answer that question a long time ago hope this helps.
A dog barks to alert his owner. What is the medium for the sound waves produced
by the dog barking? lesson 4.01
A. Air
B. ground
C. water
D. the ocean
Answer:
The Answer is ground or air
How long would it take for a sample of 222 Rn that weighs 0.750 grams to decay to 0.0469 grams, assuming the half-life of 222 Rn is 3.82 day
Answer:
Formula we will be using:
(i) ,
where
Final quantity
Initial quantity
t=time ( same unit as that of half-life)
n=half-life
-------------------------------------------------------------
Given,
Final quantity ==0.100g
Initial quantity==0.750g
Time= t(unknown)
Half-life=n=3.823 days
Plug in the above values in the formula:
Divide both sides by 0.750:
Taking natural long on both sides:
Applying
Dividing both sides by ln(0.5):
Multiplying both sides by 3.823:
11.113=t
t=11.113
It would take 11.113 days
Answer : 11.113 days
Explanation:
What type of heat transfer do
dryers use?
Forced convection
Forced radiation
Answer:I believe it forced convections
Explanation:convection is the circular motion that happens when warmer air or liquid makes something less dense.
Answer:
how y'all doinnn
Explanation:
byyeee
The diagram models how gravity works in our solar system. The sizes of the spheres are directly
proportional to their masses. The sizes of the arrows are directly proportional to force.
In what way does this diagram accurately model gravity in our solar system?
Ο Α.
by demonstrating that the force of gravity is a constant
by demonstrating that the sun controls the way that gravity affects interactions among
other bodies in the solar system
ОВ.
OOI
by demonstrating that gravity requires three or more bodies interacting with forces of
different magnitudes
by demonstrating that the strength of the force of gravity is dependent on the masses of
objects and the distance between them
OD
Answer:
by demonstrating that the strength of the force of gravity is dependent on the masses of objects and the distance between them
Explanation:
The model correctly proves gravity by demonstrating that the strength of the force of gravity is dependent on the masses of objects and the distance between them.
To model gravity, we need the mass of the objects and the distance between them.
According to Newton's law of universal gravitation "the force of gravity between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them" .
6. A serving of Cheez-Its releases 130 kcal (1 kcal = 4.18 kJ) when digested by your body. If this same amount of energy were transferred to 2.5 kg of water at 27°C, what would the final temperature be?
Answer:
78.8°C
Explanation:
Given parameters:
Amount of heat energy = 130kCal
Mass of the cheese = 2.5kg
Initial temperature = 27°C
Unknown:
Final temperature = ?
Solution:
To solve this problem, use the expression below;
H = m C (T₂ - T₁)
H is the amount of heat
m is the mass
C is the specific heat capacity of water = 4200J/kg°C
Now,
convert the amount of heat to kJ;
1kCal = 4.18KJ
130kCal = 130 x 4.18 = 543.4kJ
Insert the parameters and solve;
543.4 x 10³ = 2.5 x 4200 x (T₂ - 27 )
543.4 x 10³ = 10500 x (T₂ - 27 )
(T₂ - 27 ) = 51.75
T₂ = 51.75 + 27 = 78.8°C
PLZ HELP CHEMISTRY SUCKS BRO
Answer:
just click any of the buttons
Answer:
23535
Explanation:
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A substance that is composed only of atoms having the same atomic number is classified as
What would happen to the food chain, if all the plants were removed?
Answer: chain reaction there will be no carbon and animals who eat plants will die off
Explanation:
