Answer:
Its right
Explanation:
The chemical formula of calcium dichromate is CaCr207
An atomic model shows 19 protons, 20 neutrons, and 19 electrons. What is the mass number of the atom?
A. 39
B. 20
C. 58
D. 19
Answer:
A. 39
Explanation:
Mass number= #protons + #neutrons
19+20= 39
Taking into account the definition of mass number, the correct option is the option A: the atomic mass of the atom is 39.
First of all, all atoms are made up of subatomic particles: protons and neutrons, which are part of their nucleus, and electrons, which revolve around them. Protons are positively charged, neutrons are neutrally charged, and electrons are negatively charged (electrons).
On the other hand, the mass number tells us the total number of particles in the nucleus. That is, the mass number is the sum of the number of protons and the number of neutrons in the atomic nucleus:
Mass number = (number of protons) + (number of neutrons)
It is represented by the letter A.
In this case:
number of protons= 19number of neutrons= 20So:
Mass number = 19 + 20
Solving:
Mass number= 39
In summary, the correct option is the option A: the atomic mass of the atom is 39.
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1. A substance has a mass of 5.55 g and a volume of 3.00 cm”. Determine the density of this
substance and then use Table Sto identify the substance.
I need help please
Answer:
1.85 g per cm^3
The substance is Beryllium(if it is a single element, and not a compound)
Explanation:
PLEASE HELP ME IMPORTANT
What makes the atomic radius change along a period in the periodic table?
A. The increased atomic mass makes the atomic radius bigger.
B. More electrons in the valence shell make the radius bigger.
C. More electrons pair in orbitals, making the atomic radius smaller.
D. More protons in the nucleus pull the electrons in, making the
atomic radius smaller
Answer:
D
Explanation:
More protons in the nucleus pull the electrons in, making the atomic radius smaller. Therefore, the correct option is option D.
The atomic radius is determined by the nucleus's balance between the attracting force of positively charged protons and the repelling force of electrons.
The most crucial element in calculating the average atomic radius is not Option A. Although atomic mass typically increases with time, increasing nuclear charge has a greater impact on atomic size.
Over time, Option B has no discernible impact on atomic radius. Although the number of valence electrons changes over time, increasing nuclear charge has the biggest impact on atomic size. The valence shell is the outermost electron shell.
The gradual decrease in atomic radius is unaffected by Option C. The most frequent electron pairing occurs within orbitals of the same energy level, and it has little impact on atomic size over a period.
Therefore, the correct option is option D.
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1 teaspoon is Benefiber is added to 1 1/2 cups of water. Which of the following correctly describes what is formed?
O A. The chemical reaction between water and Benefiber allows one substance to dissolve in the other.
B. Water and Benefiber combine to form a precipitate.
o C. Benefiber is the solute in the solution that is formed.
D. Water is the solution in the solvent that is formed.
Explanation:
(A) Manganese salts give a grey borax bead test in reducing flame.
(B) From a mixed precipitate of AgCl and AgI, ammonia solution dissolves only AgCl due to the formation of [Ag(NH
3
)
2
]Cl.
(C) Ferric ions give a prussian blue precipitate on adding potassium ferrocyanide solution (D). On boiling the solution having K
+
, Ca
2+
, and HCO
3
−
ions, we does not get a precipitate of K
2
Ca(CO
3
)
2
helllllllpppppp pleeeaaassseee
Answer:
The density of ice ice is lesser than that of water that's why ice floats on water. So hence, the answer is C
Answer:
Less than that of water
Explanation:
This explains why icebergs float on water. If it was greater than that of water icebergs would sink.
If this helped please consider marking me as brainliest.
Help
I think that is C ?
Carbohydrates are like identification badges. Cells that have different membrane carbohydrates do different ________________. The immune system uses the carbohydrates to _____________________ that your cells belong to ________ and are not ______________________, ____________________, or other foreign cells..
Answer:
Ansmure two
ismirgonewart
are you
and de band
what is true beauty and the best
Explanation:
itu diatas jawaban nya
how to know that something is a basic oxide or acedic oxides?
plz help
Explanation:
General Rules. In general, the electropositive character of the oxide's central atom will determne whether the oxide will be acidic or basic. The more electropositive the central atom the more basic the oxide. The more electronegative the central atom, the more acidic the oxide.
Plz help! The best answer will be marked as brainliest!
Make a funny sentence of alloys for Magnesium
Here is an example for Mercury, it HAS to for Magnesium
“I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon”
Answer:
Sometimes the whole alloy in a uniform is a solid solution
To which family on the Periodic Table does this Bohr Model belong?
Answer:
As the valance shell have 7 valance electrons .
It belongs to halogen family (group 17).
“Chemistry is the study of all substances. Chemistry is everywhere” you think this is a good enough answer for a test about “what is chemistry?
Answer:
Try to make it more detailed "Chemistry is the study of all substances" is an amazing start. Can you give some examples of chemistry? Try to make a small paragraph.
Explanation:
Explanation:
Chemistry, the science that deals with the properties, composition, and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is released or absorbed during these processes.
This is a more detailed answer...
What type of solid contains particles that are jumbled and form no particular
pattern?
A. Crystalline
B. High-pressure
C. High-viscosity
D. Amorphous
Answer: D
Explanation:
Amorphous
Answer:D
Explanation:
took the apec test
Based on the article “Will the real atomic model please stand up?,” why did J.J. Thomson experiment with cathode ray tubes?
A. to specifically identify the nucleus as a separate part of an atom
B. to determine that electric beams in cathode ray tubes were actually made of particles
C. to prove John Dalton and Democritus wrong
D. to determine the exact energy output of cathode ray tubes
Answer:
B. to determine that electric beams in cathode ray tubes were actually made of particles
Explanation:
Answer:
B. to determine that electric beams in cathode ray tubes were actually made of particles
Explanation:
edg 2020
The ________variable is the one the experimenter has chosen to investigate
dependent
control
experimental
independent
Suleman a program is TV wacthing
Please correct me i will rate your answers
A; suleman is wacthing tv program
B;suleman is wacthing program tv
C; or no answer
Answer: A) Suleman is watching tv program
Answer this please need help right now
Objects
1. Plastic Bottle
2. Plastic Bottle
Potential energy : energy obtained due to height or position (the force of gravity)
PE = mhg
g = acceleration due to gravity (m/s²)
h = height (m)
m = mass (kg)
1. Known
m = 0.5 kg
h = 1 m
g = 9.8 m/s²
then :
[tex]\tt PE=0.5\times 1\times 9.8=4.9~J[/tex]
Kinetic energy is the energy gained by an object's motion
KE = 1/2 mv²
2. To find KE, the required data are the mass and velocity
in this table, you do not display the velocity
what are two transition metals that start with the letter R
Answer:
Ruthenium and Rhodium
Explanation:
i neeeed helllllpppppss
Answer:
the answer is 4 g/cm cube
Answer:
4g/cm cube is answer of this question
I hope it helped.
Reason. p=m/v
p=20 g/5cm cube
=4g/cm3
The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate,
Answer:the atoms of a solid aluminium can are close together vibrating in a rigid structure if the can is warmed up on a hot plate
Explanation:
The type of igneous rock which has a large number of cavities
formed by gases escaping from the molten rock is called
The answer would be scoria I believe
A driver wants to drive at a constant speed so he uses his cruise control. He wants the forces acting on him to be ___.
Group of answer choices
unbalanced
small
large
balanced
Answer:
balanced
Explanation:
A driver wants to drive at a constant speed so he uses his cruise control. He wants the forces acting on him to be balanced. Thus, the correct option for this question is D.
What is Cruise control?Cruise control may be defined as a type of system that significantly controls the speed of a motor vehicle automatically. It maintains the speed of the vehicle constant without the use of the accelerator pedal once you selected a specific speed.
The speed of the vehicle must remain constant during the course of time. This is possible when the force acting on the driver must be in a balanced state. Otherwise, it will be difficult for the driver to sustain the same speed for a long time.
Therefore, a driver wants to drive at a constant speed so he uses his cruise control. He wants the forces acting on him to be balanced. Thus, the correct option for this question is D.
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"Given a block of frozen salt water, how could you separate
pure water from the salt using only a fire & stove? Please be
as specific as you can by mentioning PHASE CHANGES.
Answer: You could put the frozen block of ice on the stove and let it melt and eventually boil out leaving the salt behind
Explanation:
How many atoms are present in 3 moles of chromium?
O 52.0 atoms
O 6.02 x 1023 atoms
O 1.80 x 1023 atoms
O 1.80 x 1024 atoms
Answer:
1.80 x 10^24 atoms
Explanation:
3moles × 6.022×10^23 atoms/mole
The nuclear equation is incomplete. Superscript 239 Subscript 94 Baseline P u + Superscript 1 Subscript 0 Baseline n yields Superscript 100 Subscript 40 Baseline Z r + blank + 2 Superscript 1 Subscript 0 Baseline n What particle completes the equation? Superscript 138 Subscript 54 Baseline X e Superscript 139 Subscript 54 Baseline X e Superscript 119 Subscript 54 Baseline X e Superscript 138 Subscript 52 Baseline T e
Answer:
The correct option is the first option
Explanation:
The equation described in the question is shown below
²³⁹₉₄Pu +¹₀n ⇒ ¹⁰⁰₄₀Zr + blank + 2¹₀n
This equation is a nuclear fission because it involves the splitting of a heavy nucleus, Plutonium (Pu), into smaller nuclei, Zirconium (Zr) and an unknown nuclei.
The law of conservation of matter states that matter can neither be created nor destroyed hence in other to get the missing atom, we must know the total number of subscripts (mass number) and superscripts (atomic number) on both sides.
The total mass number on the reactant side is 239 + 1 = 240
The total atomic number on the reactant side is 94 + 0 = 94
While, The total mass number on the product side is 100 + 2(1) = 102
The total atomic number on the product side is 40 + 2(0) = 40
To determine the missing atom, you subtract the the total atomic number of the product from that on the reactant side; 94 - 40 = 54
The atom with the atomic number 54 is Xenon,
To determine the mass number of the xenon isotope involved, you subtract the the total mass number of the product from that on the reactant side; 240 - 102 = 138.
Hence, the particle that completes the equation is ¹³⁸₅₄Xe, the first option
Answer: A on edge
Explanation:
the person above me explained it well but i wanted to shorten it.
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
Who uses petroleum and for what purpose?
Answer:
today, petroleum is mostly used as a source of energy, being rich in combustible carbon in the production of electricity or running some sorts of heat engines. ... Raw petroleum (also known as crude oil) is used in three major ways: Transportation, Electricity Generation, and Material Production.
Explanation:
hope it helps!!!!!!!!!!!!!!!!!!!!!!!!!!
A combustion reaction occurs between one molecule of methane (CHa) and two molecules of oxygen (O2).
How many atoms of carbon, hydrogen, and oxygen make up the products for this combustion reaction?
O A) 1 carbon, 1 hydrogen, and 1 oxygen
O B) 1 carbon, 1 hydrogen, and 2 oxygen
O C) 1 carbon, 4 hydrogen, and 2 oxygen
OD) 1 carbon, 4 hydrogen, and 4 oxygen
The total number of atoms make up the products :
D) 1 carbon, 4 hydrogen, and 4 oxygen
Further explanationComplete combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and O
Hydrocarbon combustion reactions (especially alkanes)
For combustion of methane (CH₄) and two molecules of oxygen (O₂).
[tex]\tt CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
The number of atoms make up the products
CO₂ : 1 carbon, 2 oxygen
2H₂O : 4 hydrogen , 2 oxygen
The total number of atoms make up the products :
D) 1 carbon, 4 hydrogen, and 4 oxygen
Combustion Reaction:Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives off heat.
Combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and OFor combustion of methane (CH₄) and two molecules of oxygen (O₂).The number of atoms make up the products:CO₂ : 1 carbon, 2 oxygen
2H₂O : 4 hydrogen , 2 oxygen
Thus, the correct option is D.
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In the rock cycle, where is the energy being released?
Group of answer choices
magma
magma to igneous
igneous to sedimentary
sedimentary to metamorphic
There's a picture of the rock cycle just so you know :)
Answer:
the two major sources of energy for the rock cycle are also shown; the sun provides energy for surface processes such as weathering, erosion, and transport, and the Earth's internal heat provides energy for processes like subduction, melting, and metamorphism.
The nucleus of an atom consists of:
a. lons & isotopes
b. Electrons & neutrons
c. Protons & neutrons
d. All of the above.
Answer:
the nucleus of an atom consistens of protons and neutrons
