Answer:
Cr2O3
Explanation:
To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:
68.4% Cr = 68.4g of Chromium
31.6% O = 31.6g of Oxygen
Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.
Cr = 68.4/52 = 1.315 mol
O = 31.6/16 = 1.975 mol
- Next, we divide each mole value by the smallest value (1.315mol)
Cr = 1.315/1.315 = 1
O = 1.975/1.315 = 1.50
The ratio or Cr to O is 1:1.5
We multiply this ratio by 2 to get the whole number ratio as follows:
2 × 1: 2 × 1.5
2:3
Hence, the empirical formula of Cr and oxygen is Cr2O3.
When an object is at rest ,we say forces are?
Answer:
If an object is at rest, then there are no forces acting on the object. It would take an unbalanced force to keep an object in motion at a constant velocity. It is the natural tendency of all objects to eventually come to a rest position.
Explanation:
What type of energy is described as electrons moving in a circuit?
Answer:
Electrical energy (form of kinetic energy)
Explanation:
In _____ , materials move from an area of higher concentration to an area of lower concentration through a cell membrane.
1.selective permeability
2.active transport
3.passive transport
How many protons, neutrons and electrons are there in a neutral Cesium atom?
55 protons, 78 neutrons, 55 electrons
69 protons, 100 neutrons, 69 electrons
37 protons, 37 neutrons, 45 electrons
43 protons, 65 neutrons, 43 electrons
Answer:
55 protons, 78 neutrons, 55 electrons
Explanation:
In a neutral Cesium atom we have 55 protons, 78 neutrons and 55 electrons. This can be found on the periodic table of elements.
Protons are the positively charged particles within an atom
Neutrons do not carry any charges.
Electrons are the negatively charged particles.
The amount of these subatomic particles can be obtained from the periodic table of element.
For a neutral atom, the number of protons and electrons are the same.
Since the atomic number is 55, it is also the number of protons in the atom.
Displacement reaction between copper and silver nitrate solution produces silver and copper (II) nitrate solution. Write the chemical equation
Answer:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
Explanation:
We are to give the reaction expression for this displacement reaction.
Reactants = copper and silver nitrate solution
Products = silver and copper (II) nitrate
Copper = Cu
Silver nitrate solution = AgNO₃
Silver = Ag
copper (II) nitrate = Cu(NO₃) ₂
So:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
How many atoms are there in 2.0 moles of magnesium (Mg)?
A. 1.2 x 1024
B. 2.0 x 1022
C. 6.0 x 1021
D. 3.0 x 1023
Answer:
It should be 1. 1.2 X 10^24
Explanation:
What is the definition of momentum?
A- The amount of matter in an object.
B-Mass in motion.
C-Speed with direction.
D- The resistance to change motion
Answer:
B. Mass in motion. Is the definition of momentum
Observe the image of sodium. List the properties you see.
Answer:
It is soft and white. It has a low melting and boiling point, a good conductor electricity, and reacts with water. Furthermore, it is also highly reactive, malleable, and ductile.
Explanation:
Hope I helped!
Answer:
silvery-white and waxy
Explanation:
Properties means the observations you can make just by looking at it or the qualities that the object has.
So when I looked at the sodium I saw a silvery-white metal (sodium is a metal), that has this waxy appearance to it.
(a)A can of soda contains 12.0 fl oz. What is the volume in liters (given
that 1 L =
1000 mL)?
Answer:
0.355L
Explanation:
1fl oz (Fluid ounce) is an unit of volume widely used in United States of America. 1fl oz is equivalent to 29.5735mL.
12.0 fl oz are:
12.0fl oz * (29.5735mL / 1fl oz) = 354.9mL
There are 354.9mL in 12.0 fl oz.
As 1L = 1000mL, in 354.9mL you have:
354.9mL * (1L / 1000mL =
0.355LWhat is the correct Lewis structure for a molecule of ammonia, NH3?
:-N-A
H-N-H
Н
H-NH
butter is made by intentionally changing the density of the milk. Try to find out how this change is made and describe it briefly. Explain these changes using particle theory
PLS HELP I RLY NEED IT :)
Answer:
As temperature increases, a substance will change from solid, to liquid, to gas. ... Apply Butter is made by intentionally changing the density of liquid milk.
Explanation:
label each as a physical or chemical change & explain your reasoning.
Answer:
1st chemical equation → Chemical change
2nd chemical equation → Physical change
3rd chemical equation → Physical change
4th chemical equation → Chemical change
Explanation:
Chemical change has to the do with the creation of an entirely new product or substance. When two reactants react and form entirely new product(s), we say that a chemical change has occurred.
While a physical change does not create an entirely new substance or product; it can only change to a new form or state.
From the given equations, we discover that in the first equation, propane reacted with oxygen to give carbon (II) oxide and water (entirely new products) while in the second chemical equation, ethanol is a liquid (at room temperature) but later changes its state to gas (physical change).
The above answer is correct.
How can the conductivity of a salt solution be decreased?
A. Add more salt to increase the concentration.
B. Add more water to decrease the concentration.
C. Add more water to increase the concentration.
D. Add more salt to decrease the concentration.
Answer:
B. Add more water to decrease the concentration.
Explanation:
If we add more water to the solution, the concentration is decreased and like wise the conductivity of the solution.
Concentration is the amount of solute in a solution. Conductivity deals with the ability of a solution to allow the passage of current.Concentration and conductivity are directly proportional to one another. The higher the concentration, the higher the conductivity and vice versa.
Adding more water increases the amount of solvent and the concentration reduces.Use the following equation to answer question 1-4. Make sure you balance first.
6HCI + Fe2O3 --> 2FeCl3 +3H2O
1. How many moles of water are produced from 10.4 moles of hydrochloric acid?
5.2 mol H₂O
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[RxN - Balanced] 6HCl + Fe₂O₃ → 2FeCl₃ + 3H₂O
[Given] 10.4 mol HCl
Step 2: Identify Conversions
[RxN] 6 mol HCl = 3 mol H₂O
Step 3: Stoichiometry
Set up: [tex]\displaystyle 10.4 \ mol \ HCl(\frac{3 \ mol \ H_2O}{6 \ mol \ HCl})[/tex]Multiply/Divide: [tex]\displaystyle 5.2 \ mol \ H_2O[/tex]What is water (H2O)? Select all that apply * an element a molecule 1 hydrogen and 2 oxygen 2 hydrogen and 1 oxygen
Answer:
2 hydrogen and 1 oxygen
Explanation:
H2O
Hydrogen has the coefficient so you multiply 1 by 2 and it equals 2
Oxygen does not have any sub or coe so its automatically 1
Particles of a liquid
A. Are free to move in a container but remain in close contact with one another
B. Are tightly packed together and stay in a fixed position
C. Have no viscosity
D. Decrease in volume with increasing temperature
Answer:
A
Explanation:
B. That's a solid
C. Liquid is the only thing that can have viscosity
D. Not necessarily the case
Covalent bonds involve the sharing of?
Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Explanation:
I hope this helps
A sample of carbon dioxide gas at a pressure of 891 mm Hg and a temperature of 84 C occupies a volume of 5.61 L. If the gas is cooled at constant pressure to a temperature of 40 C, the volume of the gas will be __ L.
Answer:
4.92L
Explanation:
Given parameters:
Initial pressure = 891mmHg
Initial temperature = 84°C = 84 + 273 = 357k
Initial volume = 5.61L
New temperature = 40°C = 273 + 40 = 313k
Unknown:
New volume = ?
Solution:
Since we are dealing with constant pressure condition, we apply charles's law.
It states that the volume of a fixed mass of gas varies directly as its absolute temperature if the pressure is constant.
Mathematically ;
[tex]\frac{V1}{T1}[/tex] = [tex]\frac{V2}{T2}[/tex]
V1 is the initial volume V2 is the new volume
T1 is the initial temperature T2 is the new temperature
[tex]\frac{5.61}{357}[/tex] = [tex]\frac{V2}{313}[/tex]
V2 = 4.92L
A 15.33 g sample of magnesium oxide is found to contain 12.67 g of magnesium. What is the percent (by mass) composition of
the magnesium in the compound?
026 Ma
Answer:
Explanation:
I can help
Answer:
12.67g of Mg / 15.33g of MgO * 100% = 82.6% of Mg
Explanation:
Give the symbol for the element with the following orbital diagram:
↑↓
1s
0000
↑↓
2s
0000
↑↓
↑↓
2p
↑↓
0000
↑↓
3s
0000
↑↓
↑↓
3p
↑↓
0000
↑↓
4s
0000
↑↓
↑↓
↑↓
3d
↑↓
↑
The given orbital diagram are iron and symbol for the element is Fe
Orbital diagrams are a pictorial description of electrons in an atom and where electron go in atom then we have to follow three rules, and the first one being the Auf bau Principle, the Auf bau Principle states that each electron occupies the lowest energy orbital first filled and the second is pauli exclusion principle in which only two electron are present which is in opposite spin and third is hunds rule of maximum multiplicity in which pairing of electron is not possible until orbital are singly occupied this rules are used for filling the electron here given orbital diagram in which 1s²2s²2p⁶3s²3p⁶4s²3d⁶ means the element is iron and symbol of this element is Fe
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when an electron gets closer to the nucleus does the attraction or repulsion grow weaker or stronger?
Answer:
Weaker
Explanation:
Since the charges on nucleus and electron are opposite in nature, an attractive force exists between them. It is true in generally, that when objects are made to move closer together in the direction of an attractive force, potential energy decreases (and increases whenever attracting objects are force to move apart).
Here, we are required to determine if the attraction or repulsion grow weaker or stronger.
When electrons get closer to the nucleus, the attraction grows stronger.First, we must establish scenarios when there can be attraction and ones where there can be repulsion.
By the law guiding electric charges; In electrical interactions:
Like poles repel while Unlike poles attract.
Also, in the atomic model; the nucleus is positively charged as it contains protons (+vely charged) and neutrons which are uncharged particles.Since the nucleus is positively charged and the electrons revolve round their orbit. Therefore, the force is an attraction force.As we all know that the force of attraction or of repulsion as the case may be is inversely proportional to the distance between the charged particles (the electrons and the nucleus in this case)When an electron gets closer to the nucleus, the distance between the electron and the nucleus reduces; and the force of attraction between the electron and the nucleus increases.Ultimately, when an electron gets closer to the nucleus, the attraction force will grow stronger due to the reduced distance between the electron and the nucleus.
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Only the ______ has successfully landed men on the moon.
Answer: The United States
The United States is the only country to have successfully conducted crewed missions to the Moon, with the last departing the lunar surface in December 1972.
Explanation:
Answer
Only the United States has successfully landed men on the moon.
Explanation:
The United States is the only country to have successfully conducted crewed missions to the Moon, with the last departing the lunar surface in December 1972.
Give 3 examples of conduction, radiation, and convection.
Answer:Conduction: Touching a stove and being burned. Ice cooling down your hand
Convection: Hot air rising, cooling, and falling (convection currents)
Radiation: Heat from the sun warming your face
Explanation:
Answer:
Radiation: Radio Waves, Conduction: An ice cube on a warm hand, Convection: A radiator
Which element below would most likely gain 3 electrons?
Answer:
Lithium
Explanation:
2. How many atoms are in 5.6 moles of Na? Answer:___3.2 E 24 atoms of Na
Answer:
5.6[tex]\frac{6.02*10^{23} }{1}[/tex] = 3.4 X [tex]10^{24}[/tex]
Explanation:
the correct answer to it is 3.4 instead of 3.2. I got 3.4 from rounding it from 3.37.
The number of atoms in 5.6 moles of Na have been [tex]\rm \bold{3.37\;\times\;10^2^4}[/tex] atoms.
Atoms have been defined as the smallest unit of matter. The number of atoms in a mole of compound has been given by Avogadro law.
According to the Avogadro law, the number of atoms in mole of sample has been equal to the Avogadro number. The values of Avogadro number has been [tex]6.023\;\times\;10^2^3[/tex].
Computation for the atoms in NaThe available moles of Na have been 5.6 moles.
The number of atoms has been given by:
[tex]\rm 1\;mol=6.023\;\times\;10^2^3\;atoms\\ 5.6\;mol=5.6\;\times\;6.023\;\times\;10^2^3\;atoms\\ 5.6\;mol=3.37\;\times\;10^2^4\;atoms[/tex]
The number of atoms in 5.6 moles of Na have been [tex]\rm \bold{3.37\;\times\;10^2^4}[/tex] atoms.
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The total mass of an atom expressed in atomic mass units is known as the *
mass number.
atomic number.
isotopic number.
covalent number.
Answer:
c
Explanation:
What is the number of protons for 2^1H?
If we react 5.4g of sodium chloride with an unknown amount of fluorine gas, we produce 4.9g of sodium fluoride and 3.7g chlorine gas. How much fluorine was consumed in the reaction?
Answer:
1.9g of F₂ were consumed in the reaction
Explanation:
Based on the chemical reaction:
2NaCl + F₂ → 2 NaF + Cl₂
Where 2 moles of NaCl react per mole of F₂ to produce 2 moles of NaF and 1 mole of Cl₂
To understand in a better way how the reaction occurs we need to convert each mass of compound to moles:
Moles of NaCl -Molar mass: 58.44g/mol-:
5.4g * (1mol / 58.44g) = 0.092 moles NaCl
Moles of NaF -Molar mass: 41.988g/mol-:
4.9g * (1mol / 41.998g) = 0.12 moles NaF
Moles of Cl₂ -Molar mass: 70.90g/mol-:
3.7g * (1mol / 70.90g) = 0.052 moles Cl₂
That means approximately 0.1 moles of NaCl react with 0.05 moles of F₂ to produce 0.1moles of NaF and 0.05 moles of Cl₂.
0.05 moles of F₂ are:
0.05 moles * (38g/mol) =
1.9g of F₂ were consumed in the reactionWhich of these is a characteristic of science? (5 points) Question 1 options: 1) It cannot be reproduced by any scientist. 2) It cannot be changed by new knowledge. 3) It is based on empirical evidence. 4) It is guided by a set of values.
Answer:
3
Explanation:
It is based on empirical evidence
The characteristic of science is that it is based on empirical evidences comprising of a hypothesis.
What is a hypothesis?
Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
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What is the atomic number of silicon
Answer:
The atomic number of silicon 14
According to periodic table
The atomic number of silicon is 14
Hope it helps:)