Answer:
An ice cube melting is a physical change because melting doesn't change the composition of the element. Paper burning is a chemical change because combustion occurs. Bubbles forming in a soda does involve chemical changes. Hard-boiling an egg is a chemical change because the egg's composition changed.
True or false The atomic number of an element is always more than the mass number of that element.
What is one characteristic that makes Earth capable of supporting life?
A. It has ocean currents that circulate water from pole to pole.
O B. It has a strong magnetic field that protects organisms from
harmful radiation.
C. It is in a solar system located in one of the outer arms of a spiral
galaxy
D. It has more mass than any of the other planets of the inner solar
system.
Answer:
it is option (d)
it has more mass than any of the other planets of the inner solar system
Which general equation shows a double-displacement reaction?
O A. AB + CD + AC + BD
O B. AB → A+B
O C. AB + CD → AD + CB
O D. A+B → AB
Answer:
O A. AB + CD + AC + BD
explanation:
Explanation:
A.ab+cd+ac+bd is your answer
The laboratory test of a patient shows blood calcium level of 8.8meq/l. How many moles of calcium ions are in 0.50l of blood?
Answer:
2.2 × 10⁻³ mol
Explanation:
Step 1: Calculate the number of equivalents in 0.50 L of blood
The blood calcium level of 8.8 meq/L.
0.50 L Blood × 8.8 meq/L = 4.4 meq = 4.4 × 10⁻³ eq
Step 2: Calculate the number of moles of calcium
Calcium has a charge of 2. Thus, it has 2 equivalents per mole.
4.4 × 10⁻³ eq × 1 mol/2 eq = 2.2 × 10⁻³ mol
(d) (i) How can the water molecules from the iceberg end up as water in the lake?
Explanation:
If the iceberg is near the lake and the water molecules melt, then the molecules will slide down. The iceberg could be melting for many reasons - it can be purposely destroyed, the sun could be melting it, or it might naturally fall in. So, this is the answer to your question. Hope it helps!
The Austrian monk and scientist Gregor
studied the traits of pea plants. He could see that pea plant traits were passed from parents to offspring in a process called
.
Answer:
Mendel, Inheritance/Heredity
Explanation:
Gregor Mendel (1822-1884) was an Austrian monk and scientist as stated in this question. He is referred to as the FATHER OF GENETICS due to his immense contributions to the principle of inheritance.
Gregor Mendel via his several works conducted on pea plants was able to demonstrate how traits passed down from parents to offsprings in a process called INHERITANCE OR HEREDITY.
Your Answer is : 1st Mendel and 2nd heredity.
Explanation:
The first excited state of a particular atom in a gas is 6.1 eV above the ground state. A moving electron collides with one of these atoms, and excites the atom to its first excited state. Immediately after the collision the kinetic energy of the electron is 3.2 eV. What was the kinetic energy of the electron just before the collision
Answer:
The kinetic energy of the electron just before the collision is 9.3 eV.
Explanation:
We can find the kinetic energy of the electron before the collision can be found by energy conservation:
[tex] E_{i} = E_{f} [/tex]
[tex] K_{a_{i}} + K_{e_{i}} = K_{a_{f}} + K_{e_{f}} [/tex] (1)
Where:
[tex]K_{a_{i}}[/tex]: is the initial kinetic energy of the atom
[tex]K_{a_{f}}[/tex]: is the final kinetic energy of the atom = 6.1 eV + [tex]K_{a_{i}}[/tex]
[tex]K_{e_{i}}[/tex]: is the initial kinetic energy of the electron =?
[tex]K_{e_{f}}[/tex]: is the final kinetic energy of the electron = 3.2 eV
By solving equation (1) for [tex]K_{e_{i}}[/tex] we have:
[tex]K_{a_{i}} + K_{e_{i}} = (6.1 eV + K_{a_{i}}) + 3.2 eV[/tex]
[tex] K_{e_{i}} = 6.1 eV + 3.2 eV = 9.3 eV [/tex]
Therefore, the kinetic energy of the electron just before the collision is 9.3 eV.
I hope it helps you!
True or false, Henry Moseley discovered through X-Ray crystallography the number of neutrons that were present
in the nucleus of atoms of every element.
Answer:
Im pretty sure its true
Explanation:
Answer:
answer is true .
Explanation:
this may help you
Raw material for rayon comes from
a.cellulose
b.coal
c.petroleum
d.animal bones
Explanation:
the raw material for the rayon come from is cellulose
What are two factors that determine the concentration of hydronium (or hydroxide) ions in an acid (or base) solution?
Answer:
hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water (Kw). The concentrations of these ions in a solution are often critical determinants of the solution’s properties and the chemical behaviors of its other solutes, and specific vocabulary has been developed to describe these concentrations in relative terms. A solution is neutral if it contains equal concentrations of hydronium and hydroxide ions; acidic if it contains a greater concentration of hydronium ions than hydroxide ions; and basic if it contains a lesser concentration of hydronium ions than hydroxide ions.
Answer:
hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water
Explanation:
Not my work! I hope this helps!
If aluminum is placed in an aqueous solution of silver nitrate and a single replacement reaction happens, what would be the balanced equation to represent the reaction?
Answer:
The balanced equation would be:
3AgNO3+Al→3Ag+Al(NO3)3
Explanation:
Select from below all elements that follow the DUET rule (not the octet rule). (you can select multiple)
a) Li
b) Mg
c) O
d)He
e) H
f) Ne
Calculate the number of phosphorus atoms in 6.2g of phosphorus
Answer:
9.33 e22
Explanation:
For moles
N=m/M
N=6.2/40
N=0.155
For total no. Of atoms:
Atoms= N × 6.02e23
Atoms= 0.155× 6.02e23
Atoms= 9.33e22
Using the balanced equation below, how many grams of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride?
CSF + XeF6 → CsXeF7
Answer:
27.9 g
Explanation:
CsF + XeF₆ → CsXeF₇
First we convert 73.1 g of cesium xenon heptafluoride (CsXeF₇) into moles, using its molar mass:
Molar mass of CsXeF₇ = 397.193 g/mol73.1 g CsXeF₇ ÷ 397.193 g/mol = 0.184 mol CsXeF₇As 1 mol of cesium fluoride (CsF) produces 1 mol of CsXeF₇, in order to produce 0.184 moles of CsXeF₇ we would need 0.184 moles of CsF.
Now we convert 0.184 moles of CsF to moles, using the molar mass of CsF:
Molar mass of CsF = 151.9 g/mol0.184 mol * 151.9 g/mol = 27.9 g Help ASAP only right answers only no spam don’t answer if you don’t know
…..
Answer:
Inference
Explanation:
I mean, it's not difficult.
A theory is an unproven explanation.
An inference is a guess/educated guess where you don't have all the facts.
For example, if "Bob" is caught in the kitchen with a ketchup stain on his shirt, you are inferencing that he used the ketchup.
However, if you see a ketchup bottle nearby or saw it earlier, then it is not, because you already have the facts that ketchup was used.
Which of the following statements regarding diffusion is false? Group of answer choices Diffusion is a result of the thermal energy of atoms and molecules. Diffusion occurs even after equilibrium is reached and no net change is apparent. Diffusion requires no input of energy into the system. Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
Answer: The statement diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated, is false.
Explanation:
When particles or atoms of a substance are able to move rapidly from one place to another then it is called diffusion.
During diffusion, particles tend to move apart from each other.
For example, spreading of dye molecules into water.
Thus, we can conclude that the statement diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated, is false.
how many distinct monochlorinated products can result when methylcyclohexane is subjected to free radical chlorination under UV light
Answer:
How many distinct monochlorinated products can result when methylcyclohexane is subjected to free radical chlorination under UV light.
Explanation:
Consider 1-methylcyclohexane:
Its structure is shown below:
It has primary [tex]1^o[/tex], secondary [tex]2^o[/tex]and tertiary [tex]3^o[/tex] carbons as shown in the image.
So, the following mono chlorinated product will be formed.
what is the application of chemistry
Answer:
Chemistry plays an important and useful role towards the development and growth of a number of industries. This includes industries like glass, cement, paper, textile, leather, dye etc. We also see huge applications of chemistry in industries like paints, pigments, petroleum, sugar, plastics, Pharmaceuticals.
Methane is the main component of natural gas. Using the given reaction enthalpy, calculate the heat energy produced by the combustion of one kilogram of methane.
Answer: The heat energy produced is 53831.25KJ
Explanation:
METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:
Molecular mass of methane =16 gm/mol.
So moles of 1 kg methane =
Given mass of methane ÷ molecular weight of methane
But the given mass = 1kg = 1000g
Therefore,
moles of 1000g methane = 1000÷16
= 62.5 moles
Hence, energy evolved = (moles of methane) × (heat of combustion)
Therefore,
heat energy produced= 62.5 × (-861.3kj)
= -53831.25kj
The heat energy produced by the combustion of one kilogram of methane is –53831.25 KJ
We'll begin by calculating the number of mole in 1 Kg of CH₄
Mass of CH₄ = 1 kg = 1000 g
Molar mass of CH₄ = 12 + (4×1) = 16 g/mol
Mole of CH₄ =?Mole = mass /molar mass
Mole of CH₄ = 1000 / 16
Mole = 62.5 moles Finally, we shall determine the heat energy produced from the reaction.CH₄ + 2O₂ —> CO₂ + 2H₂O ΔH = –861.3 KJ
From the balanced equation above,
1 mole of CH₄ reacted to produce –861.3 KJ.
Therefore,
62.5 moles of CH₄ will react to produce = 62.5 × –861.3 = –53831.25 KJ
Thus, –53831.25 KJ of heat energy is produced.
Complete Question is located in the attached photo
Learn more: https://brainly.com/question/13671340
The table shows the charge on three unknown subatomic particles.
X positive
Y no charge
Z negative
Which particle is most likely present in the space outside of the nucleus of the atom?
Answer:
Z negative
Explanation:
The negative charge shows that this is an electron. Electrons are present outside the nucleus of the atom and having negative charge. Usually represented by e-
Answer:
Only Z?
Explanation:
please provide is matter about us pure all NCERT questions and answers
Answer:
I hope that's what u were lookong for :))
Explanation:
Aluminum hydroxide, with heat, creates__
Which of the following
Combination,decomposition,
Single replacement,
Double replacement,
Combustion
Answer: Decomposition is the answer
Explanation: why because aluminium hydroxide would decomposes in the presence of heat and would form an oxide which is aluminium oxide and would also form water as a product.
HOPE THIS HELPS!!
If a reaction occurs, what will be the products of the unbalanced reaction below?
Cu(s) + Ni(NO3)2(aq)
The Activity Series of Elements
A.
CuNi(NO3)4(s)
B.
Ni(s) + Cu(NO3)2(aq)
C.
No reaction will occur.
D.
CuNi(s) + NO2(g)
Cu(s) + Ni(NO3)2(aq) ⇒Ni(s) + Cu(NO3)2(aq)
The answer is option B.
What is electrochemical series?
Electrochemical or hobby series when the electrodes (metals and non-metals) in touch with their ions are organized on the idea of the values of their preferred discount potentials or standard oxidation potentials, the resulting series is called the electrochemical.
The electrochemical series is built up by means of arranging various redox equilibria so as of their fashionable electrode potentials (redox potentials). The maximum poor E° values are placed at the pinnacle of the electrochemical series, and the maximum wonderful at the lowest.
Learn more about chemical equation here:-https://brainly.com/question/11231920
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What mass of barium sulfate (233 g/mol) is produced when 125 mL of a 0.150 M solution of barium chloride is mixed with 125 mL of a 0.150 M solution of iron(III) sulfate
Answer:
4.37 g of barium sulphate
Explanation:
The reaction equation is;
3BaCl2(aq) + Fe2(SO4)3(aq) ---->3 BaSO4(s) + 2FeCl3(aq)
From the question, the number of moles of both barium chloride and FeSO4 = 125/1000 L × 0.150 M = 0.01875 moles
To find the limiting reactant;
3 moles of barium chloride yields 3 moles of barium sulphate
0.01875 moles of barium chloride yields 3 × 0.01875 moles/3 = 0.01875 moles of barium sulphate
1 mole of iron III sulphate yields 3 moles of barium sulphate
0.01875 molesof iron III sulphate yields 0.01875 moles ×3/1 = 0.05625 moles of barium sulphate
Hence,barium chloride is the limiting reactant
Amount of barium sulphate produced = 0.01875 moles × 233 g/mol = 4.37 g of barium sulphate
Blood tests can be used to check a person's blood glucose and hormone levels. The tabular column given below shows the result of two blood tests carried out on three people to check their blood glucose levels. Person 1 is healthy
Answer:
In after fasting test, Person 2 has slightly higher blood glucose level than person 1.
In after drinking glucose test, Person 3 has much high glucose level than person 1.
Explanation:
Blood sugar test determines the level of glucose present in body. The test can be taken after intake of food / glucose or after fasting for 12 hours. Results of both tests are compared to identify level of glucose present in human body. In after fasting test person has higher glucose and in another test person 3 has higher glucose level.
Which drawing is structural model of C3H8?
Answer:
option B is the correct answer
14. Which of the following alkanols on oxidation is most likely to yield the
compound below?
CHICHICOOON
.CO
(A) Butanol (B) Propan-2-ol(2-methylbutan-1-ol (D) 2-methylpropan-1-
ol (E) 2-methylpropan-2-ol.
Answer:
A
Explanation:
I think that is the ans but am not sure
Answer:
2-methylpropan-1-ol.
Explanation:
[tex]{ \tt{CH _{3}CH(CH _{3})CH _{2}OH}}[/tex]
need help really quickly!!
so how do you predict products when only reactants are given?
i can do everything else that’s asked for the hw but i don’t know how to do this one.
the first pair of reactants is calcium hydroxide + ammonium chloride.
Answer: so in this question are reactants are calcium hydroxide and ammonium chloride
Explanation: first of all know that a salt would be formed so here the salts present are calcium and chloride so they would react to form the salt calcium chloride, then since ammonium ions are present ammonia gas would be formed then, hydroxide ions (OH) are also present so water would be formed so our final products would be calcium chloride , ammonia and water .
WORD EQUATION
calcium hydroxide+ ammonium chloride⇒ calcium chloride+ ammonia+ water
CHEMICAL EQUATION
CA(OH)2+2NH4CL⇒ CACL2+2NH3+2H2O
Which redox reaction would most likely occur if silver and zinc metal were added to a solution that contained silver and zinc ions?
Answer:
D. Zn²⁺ + 2Ag → Zn + 2Ag⁺
Explanation:
On the reduction potential chart, we have that silver ion Ag⁺ is a stronger oxidizing agent than, zinc, Zn, which is a reducing reducing agent the compared to silver
Therefore, the redox reaction that will occur is that the zinc, Zn, will be oxidized to Zn²⁺ ion, while the silver, Ag²⁺ ion will be reduced to silver deposits Ag, therefore, the zinc will displace the silver in the solution containing silver and zinc ions because zinc is higher than silver in the reactivity series
The reduction potential Zn → Zn²⁺ + 2e⁻ = +0.76
The reduction potential for Ag⁺ + e⁻ → Ag = +0.8
Therefore, given that redox reactions are reversible, we get the following likely redux reaction;
Zn(s) + 2Ag⁺(aq) ⇄ 2Ag(s) + Zn²⁺(aq)
Therefore, from the given options;
Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq) is the reaction most likely to occur.
If a substance contains ionic bonds, then its properties would include
Answer:
If the substance has high melting/boiling point, if it requires high temperature to dissociate into simpler particles, if it's structure is hard and if it conducts heat and electricity quite frequently, then it would be "Ionic compound" otherwise, it will be covalent compound.Explanation:
If a substance contains ionic bonds, then it’s properties would include high melting and boiling points, a crystalline structure, the ability to dissolve quite easily in water, the ability to conduct electricity, have good insulation and lastly be quite hard and brittle.
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