Answer:
29
Explanation:
Copper is a chemical element with the symbol Cu and atomic number is 29
Explanation:
calculate the pH of 500cm3 of 0.2mol/dm3 Ca(OH2), assume complete ionisation
Answer:
The pH of 500 cm³, 0.2 mol/dm³, Ca(OH₂) is ≈ 13.6
Explanation:
The given parameters are;
Concentration of the calcium hydroxide, Ca(OH₂) = 0.2 mol/dm³
Volume of the calcium hydroxide, Ca(OH₂) = 500 cm³
Given that the calcium hydroxide, Ca(OH₂), undergoes complete ionization in water, complete dissociation, we have;
Ca(OH₂) ⇄ Ca²⁺ + 2 OH⁻
Therefore, we have;
2 moles of [OH⁻] for each mole of Ca(OH₂) which gives the concentration of [OH⁻] as
[OH⁻] = 2 × 0.2 ≈ 0.4 mol/dm³
The pH is given by the formula
pH = 14 + ㏒₁₀ [OH⁻]
pH = 14 + ㏒₁₀ (0.4) = 14 - 0.3979 = 13.6021 ≈ 13.6
The pH of the 500 cm³ 0.2 mol/dm³ Ca(OH₂) ≈ 13.6.
What happens when two objects when they are brought closer together The mass of both objects decrease The mass of both objects increase The gravitational force between them decreases The gravitational force between them increases
Answer:
The correct option is
The gravitational force between them increases
Explanation:
According to Newton's law of universal gravitation states that the force of attraction between two bodies is directly proportional to the product of the masses of the bodies and inversely proportional to the square of the distance of their centers from each other.
The formula for universal gravitation is given as follows;
[tex]F_{1} = F_{2} =G \times \dfrac{m_{1} \times m_{2}}{r^{2}}[/tex]
Where;
F₁, and F₂ = The gravitational forces of attraction on each mass
G = The gravitational constant
m₁ = The mass of one body
m₂ = The mass of the body
r = The distance between the centers of the two bodies
Therefore, the gravitational force of attraction on each object is inversely proportional to the as the distance between the centers of the two bodies
When the distance between the centers of the two bodies decreases, the two objects are brought closer together, the gravitational force of attraction between them increases.
Answer:
Gravitational force between two objects of masses m1/m2
Explanation:
is defined by Gm1xm2/r^2, where G is a universal constant, and r is the distance between the masses. This shows you why B is wrong; it would increase. Also, A is not a good choice, as shown. In the case of B, it would increase by say, 2/1 to 4/1 by doubling ones mass. In C's case the bottom would decrease on the fraction alot (square) if they were moved closer, thus the force would be greater.
Explanation:
in other words the answer is The gravitational force between them increases
I'll GIVE BRAINLIEST: In a redox reaction, CO is changed to CO2. How many electrons must be lost or gained by C and why?
Answer:
C is gaining 2 electrons
Explanation:
O has a 2- charge so for CO to pick up another O atom would add 2 more electrons.
Answer:
C gains 2 electrons
Explanation:
In the redox reaction, CO is changed into CO2 which means there is an additional oxygen. Oxygen loses 2 of its electrons in order to neutralize. So, C must be gaining 2 electrons in order to make the bond.
PLEASE HELP WILL GIVE BRAINLIEST!!!!
If the concentration of substance A of a reversible reaction in dynamic equilibrium increases, how will the equilibrium change?
A. It will shift to create more of substance A.
B. It will shift towards the reactants.
C. It will shift towards the products.
D. It will shift to create less of substance A.
Answer:
[tex]\boxed{It\ will\ shift\ to\ create\ less\ of\ substance\ A}[/tex]
Explanation:
If the concentration of any substance A in a dynamic equilibrium increases, The equilibrium will be shifted to its opposite side so that Substance A can be created less and the substance opposite to A can be created more so that a "dynamic equilibrium" can again be established.
0.024 is how many significant figures?
Answer:
24×10^-3Explanation:
[tex]Move \: the\:decimal \:point\:,\\3 \:times\:to\:the \:right = 24\\\\When \:the\:decimal\:point \: moves\\\:to\:the \:right\:it\:becomes\:a \:negative\:power\\\\0.024= 24 \times 10^-^3[/tex]
An element’s most stable ion forms an ionic compound with bromine, having the formula XBr2. If the ion of element "X" has a mass number of 230 and has 86 electrons, what is the identity of the element, and how many neutrons does it have?
Answer:
88
Explanation:
The ion has a charge of 2+, therefore the number of neutrons it possess is 86+2
which equals 88
The element X having a mass number of 230 and has 86 electrons is radium and has 142 neutrons.
An atom is composed basically of electrons, protons and neutrons. In a neutral atom, the number of protons and electrons are equal. The number of neutrons is the difference between the mass number and the number of protons (atomic number).
Since we know that the ion of the element X has 86 electrons and the compound formed is XBr2, it then means that neutral X has 88 electrons.
The number of electrons in the neutral atom is the same as the number of protons or atomic number. An element can be identified by its atomic number. The element having atomic number 88 is radium.
The number of neutrons is obtained as;
Mass number - atomic number
230 - 88 = 142 neutrons
Learn more: https://brainly.com/question/803445
which of the following molecules would you expect to be optically active
1. CCl2F2
2. 2-methyl butane
3. butan-2-ol
Answer:
waaaaaaaaaaqwwwwwwwwwwww
How many moles are present in 136 grams of MgCl2? 1.46 mol 1.43 mol 2.27 mol
Answer:
1.43 mol
Explanation:
percentage of carbon in urea
The percentage of carbon in urea is [CO(NH 2) 2] is 20%
.hlp me to solve mcq
Answer:
i) b
ii) c
Explanation:
Please see attached picture for full solution.
How can you use the scientific method in everyday life?
You can use the scientific method everyday by asking questions and doing experiments. For example, you want to know how a fire starts, so you do an experiment with it!
List the metals Mg, Cu, Au, Na and Al in the decreasing order of their reactivity with air.
Answer:
Na is most reactiveAlcuAu is less reactiveIN HEREAnswer:
Potassium (K)
Sodium (Na)
Calcium (Ca)
Magnesium (Mg)
Aluminium (Al)
Iron (Fe)
Lead (Pb)
Copper (Cu)
Silver (Ag)
Gold (Au)
1. Which material had the highest rate of absorption? What can you conclude about the rate
of absorption in the natural world? How might this influence climate regions?
it might be porous materials
Answer:
Air had the highest rate of absorption. Air absorbs most of the suns heat and sun rays and air can move to different areas which are warm and colder.
Explanation:
What is ionic bond and explain it
Answer:
An ionic bond is a chemical bonding involving the attraction between oppositely charged ions
Explanation:
On the periodic table, elements from group 1 and 7 are attracted to each other and when they bond, it's called ionic bonding. This is because of their valence electrons and ions.
Answer:
Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds. It is one of the main types of bonding along with covalent bonding.
Which of the following elements has a complete outer shell of electrons? A. Iron (Fe) B. Hydrogen (H) C. Neon (Ne) D. Nitrogen (N)
Answer:
The answer is Neon
Answer:
neon
Explanation:
neon has a complete outer 2n shell
If an object's mass is 70 g, and its volume is 10cm cubed, what is its density?
If an object's mass is 70 g, and its volume is 10cm cubed, its density is 7 centimeter cube.
What is density?The density of any solid substance is the unit of the area occupied by it in per centimeter of the cube of the volume in the given sample and calculated by dividing the mass and the volume of the compound unit will be centimeter cube.
The mass of the given object is 70 gram and the volume is given is 10 cm to find the density,
Density = mass of object / volume of object
substituting the value in the formula,
Density = 70 / 10
Density = 7 centimeter cube.
Therefore, the density of the given object will be 7 centimeter cube if an object's mass is 70 g, and its volume is 10cm cubed.
Learn more about density, here:
https://brainly.com/question/15164682
#SPJ2
Please help me...
Atoms of elements X, Y and Z have 16, 17 and 19 electrons, respectively. Atoms of argon have 18 electrons.
a Determine the formulae of the compounds formed by the combination of the atoms of the elements:
(i) X and Z
(ii) Y and Z
(iii) X with itself.
b In each of the cases shown in
A (i)–(iii) above, name the type of chemical bond formed.
c Give two properties you would expect to be shown by the compounds formed in an (ii) and an (iii).
Answer:
a 1) XZ2
2) YZ
3) X2
b 1) Ionic bond
2) Ionic bond
3) covalent bond
c) ionic compounds has high melting and boiling point
ionic compounds can conduct electicity in aqueous form
covalent compounds have electrons shared between the atoms
covalent compounds have lower melting point compared to ionic compound
Answer:
(i) XZ = Potassium Sulfide [K2SO4]
(ii) YZ = Potassium Chloride [KCI]
(iii) X = Sulfur [S]
b) (i) Ionic Bond. (ii) Ionic Bond. (iii) Covalent Bond.
c) (i) Ionic compounds have high melting and boiling points.
(ii) Ionic compounds can conduct electricity in a molten state or a solution as they have ions that can move and carry charge.
(iii) Covalent compounds have low melting and boiling points.
(iv) Covalent compounds can not conduct electricity as all electrons are involved in bonding so there are no free electrons or ions to carry the charge.
Hope this is OK :))
Please mark me as Brainliest:))
anyone knows how to do this-
Explanation:
The number of protons in the element C^12 (Carbon) is 6, number of electrons 12 and number of Neutrons is 6, same as the number of protons it contains
C^13 has 13 electrons, 6 protons and 7 Neutrons this one's neutron number is different from proton number because it's an isotope
Na^-1 has gained an electron so the number of electrons it has = 24 and the number of protons shown as 11 which means there are 23 - 11 = 12 Neutrons
O^-2 has gained two electrons and got 18 electrons in total, 8 protons and 8 neutrons
Tips for memorizing the first 20 elements of the periodic table?
Answer:
hydrant flying with balloon, balloon has lithp letting air out, bee: really yum balloon
= = = =
hydrogen helium lithium beryllium
be bore on the balloon, balloon pops, hydrant drops and makes a car bomb
= =
boron carbon
night row general gets hurt by car bomb nearby, that general gets off boat
=
nitrogen
wearing oxygen mask, mask is full of fluride gel, then he got neon teeth
= = =
oxygen fluorine neon
(try making a story out of the elements, use your imagenation)
I will give u tips to learn whole periodic table
1. Break down the table into sections
2. Spread out the memorisation process
3. Learn the elements in a song
4. Make none sense words made from element symbols
5. Use colour to learn element groups
6. Use mnemonic device to help remember the order of elements
I am sure this will be helpful for uuu
Explanation:
how many oxygen atoms are in 7.25g of calcium nitrate
Answer:
The answer to this question is approximately equal to 1.6 ×
[tex] 1.6 \times {10}^{23} atom \: o[/tex]
What are the properties of alkynes
Which is the correct definition of metallic bonding? Select one: a. an array of positive ions in a sea of electrons b. complete transfer of valence electrons c. atoms share electrons to to be stable
Answer:
I believe it's A) an array of positive ions in a sea of electrons
Explain how the energy of a toy car is transformed as it slides down a ramp. Give evidence that the energy of the car remains the same at all points on the ramp. (30 points)
Answer:
As the car starts to slide down the ramp, it is kinetic energy and when it's on the top of the ramp, it is potential energy. We can see that the energy is now being transferred through the car and ramp.
Ou Esaplain different form
of oxygen?
Answer:
oxygen is the chemical element with the atomic number is 8 and the symbol is o its known as called oxygen.
Explanation:
Oxygen is the most third element in the universe at they standard and temperature and pressure,and oxides most elements as other compounds.
Oxygen gas is the earth atmosphere is 21%, an oxygen is the half of the earth crust in form of oxide,oxygen is liquid and solid gas.
Oxygen atoms such as proteins and acids, fats the major organic compounds, oxygen as component of the water and carbon dioxide.
Oxygen has many characteristics :- properties and molecular structure:-
this is a pressure and temperature with molecular formula referred as oxygen,simply describe a double bond and molecular orbits.
Physical properties:- oxygen is highly substance and must be combustible materials, oxygen may also from using a liquid nitrogen coolant, molecular oxygen is the associated with the process of air glow.
Stellar origin :- all of the remaining to half lives to the majority of are less then milliseconds.
Occurrence:- oxygen is the process part of the element in the earth crust, free oxygen is also occurs in the world bodies.
Analysis :- analysis to the structure of vegetation and the carbon cycle on a global scale.
Ytu perform an electrolysis reaction using FeCl, iron (1) chloride. Which of the following will happen?
A. Chlorine will move to the positive electrode and become reduced.
B. Iron will move to the positive electrode and become oxidized.
C. Chlorine will move to the negative electrode and become oxidized.
D. Iron will move to the negative electrode and become reduced.
Answer:
The answer is "Option B"
Explanation:
when we react with FeCl, iron, and chloride to both the electrolysis. So, iron is charged positive ion, as well as passes to the negative, is cathode electrode. But there is a decrease in the cathode.
The equation can be defined as follows:
[tex]FeCl_2[/tex] [tex]\longrightarrow[/tex][tex]Fe + Cl_2[/tex]
In the above equation, when the iron chloride electrolysis solution, it will give the iron(II) and the chlorine. This process happens when the hydrogen chloride solution at a temperature of about 90 ° C.
Answer: D
Explanation: As Fe is positive charged while chlorine is negative charged.
(D) is correct. As iron moves to negative and it get reduce as negative electrode is cathode
If a gas displays a solubility of 0.00290M at a partial pressure of 125 kPa, what is the proportionality constant for this gas in this solvent and at this temperature?
Answer:
The proportionality constant ( Henry’s constant) = 2.32 * 10^-5 M/kPa
Explanation:
Here in this question, we are concerned with calculating the proportionality constant for this gas.
Mathematically, we can get this from Henry law
From Henry law;
Concentration = Henry constant * partial pressure
Thus Henry constant = concentration/partial pressure
Henry constant = 0.00290 M/125 kPa = 2.32 * 10^-5 M/kPa
Select the correct answer from each drop-down menu. At chemical equilibrium, the amount of because .
Answer:
The answer that completes the question are in BOLD:
At chemical equilibrium, the amount of PRODUCT AND REACTANT REMAIN CONSTANT because the RATES OF THE FORWARD AND REVERSE REACTIONS ARE EQUAL.
Explanation:
In a reversible chemical reaction, an equilibrium is said to be achieved when the rates of the forward reaction is equal to that of the reverse reaction. A reversible reaction is one in which products are formed from reactants simultaneously with the formation of reactants from products.
The combination of two or more substances called REACTANTS gives rise to another substance called PRODUCT, which can in turn give rise to Reactants again. With time, the rate at which the reactants give rise the products, which is called the FORWARD REACTION will be equal to the rate at which the products give rise to the reactants, which is called REVERSE REACTION. At this point, the chemical reaction is said to be in a STATE OF EQUILIBRIUM.
When the rate at which both reaction occurs becomes equal i.e. at an equilibrium state, the concentration of both the reactants and the products becomes constant i.e. no longer changes. Hence, the amount of the reactants forming the products is the same as the amount of products forming the reactants.
N.B: At chemical equilibrium, the amount of the reactants and products does not necessarily equals zero (0). It simply means that there is no net change in the concentration/amount of both reactants and products.
What would be the pH of an HNO3 solution if the [H+] = 3.26 x 10-6 moles/liter? 5.49 4.67 6.32
Answer:
5.49
Explanation:
pH = - log[3.26 x 10-6] =5.49
the overall take away of an experiment’s results is the______. A. hypothesis B. introduction C. conclusion
Answer:
conclusion
Explanation:
it can't be a hypothesis since tests are carried out to verify so it is not a theory
an introduction to an experiment only gives the basis of what we are investigating therefore nothing has been proven and the question is still unanswered
The overall takeaway of an experiment’s results is the conclusion. Hence, option C is correct.
What is a hypothesis?A hypothesis is a testable statement about the relationship between two or more variables or a proposed explanation for some observed experiment.
The overall takeaway of an experiment’s results can't be a hypothesis since tests are carried out to verify so it is not a theory
An experiment only gives an idea about the investigation therefore nothing has been proven and the question is still unanswered.
Hence, the overall takeaway of an experiment’s results is the conclusion.
Learn more about the hypothesis here:
brainly.com/question/5177511
#SPJ5
If you are designing an experiment, how will you determine your independent or dependent variable?
Answer:
The independent variable effects the dependent variable.
Explanation:
The independent variable Is what you change whereas the dependent variable would change because of that.
for example, the indipendent variable could be how much you water a plant in ml each day, and the dependent variable would be how tall each plant grown]s with that water doseage per day.
