Answer: According to the reactivity of metals Sodium is the second metal while Magneesium is the fourth metal. The metal in the top of the reactivity serise table are more reactive.
(The series obtained by the arrangement of metals in the decending oder of their reactivity is the REACTIVITY SERIES TABLE)
Explanation:
K
Na
Ca
Mg
Al
Zn
Fe
Sn
Pb
H
Cu
Hg
Ag
Pt
Au
Therefore Sodium is more reactive than Magnesium
Answer:
The alkaline-earth metals tend to lose two electrons to form M 2+ ions (Be2+, Mg2+, Ca2+, and so on). These metals are less reactive than the neighboring alkali metal. Magnesium is less active than sodium; calcium is less active than potassium; and so on. These metals become more active as we go down the column.
a beam balance is called a first class lever why?
Answer:
A beam balance is an example of a first class lever.
Explanation:
A beam balance is an example of a first class lever. In a first class lever, the fulcrum is between the effort (force) and the load. The effort (force) moves over a large distance to move the load a smaller distance.
Other examples of first class lever are pliers, scissors, a crow bar, a claw hammer, a see-saw and a weighing balance etc.
chemistry class 9 chapter 1
Explanation:
i) Melting point = 15°C and Boiling point = 110°C
ii) The region C on graph there is only liquid state, the region A on graph there is only solid state.
iii) The straight line A1 - B1 shows that the melting point of solid wax and getting converted to liquid form.
iv) Latent heat of vaporization is a physical property of a substance.
It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure.
v) At 'B' the wax is at both solid and liquid state
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
Which of the following numbers is equal to the value snow
notation below?
4.8 x 10^-4
A. 0.0048
ОО
B. 0.00048
C. 0.048
D. 0.000048
Answer:
B
Explanation:
4.8×10^-4
10^-4 = 0.0001
4.8×0.0001 = 0.00048
Ecstasy is one example of which of the following?
Depressants
Narcotics
O Club drugs
Stimulants
Answer:
Narcotics
I think ans is
Explanation:
tropicaia
Ecstasy, also known as MDMA, is used recreationally, so it can be called a club drug. However, it is illegal in the US, so it would be considered a narcotic as well. The effects it has are also of the stimulant variety, so they would fall under that category as well. It is definitely not a depressant.
Calculate the numerical Kc value for the following reaction if the equilibrium mixture contains 0.51 M CO , 0.30 M H2 , 1.8 M CH4 , and 2.0 M H2O.
CO(g) + 3H2 (g) ⇌ CH4 (g) + H2O (g)
Show work
Answer:
uh i think this is the answer
Explanation:
PLEASE HELP
Which of the following correctly orders the types of radiation from the LONGEST wavelength to the SHORTEST wavelength?
A. Green Visible Light, Red Visible Light, Blue Visible Light, Ultraviolet
B. Microwave, Orange Visible Light, Ultraviolet, Violet Visible Light
C. Red Visible Light, Infrared, Microwaves, Radio waves
D. Microwave, Blue Visible Light, Ultraviolet, Gamma
Answer:
D. Microwave, Blue Visible Light, Ultraviolet, Gamma
Explanation:
colors longest to shortest are
red green blue violet
longest wavelength to shortest:
radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays.
Why are measurements important for science?
Pleaseee help me :( give two reasons why it's important
Answer:
measurements are important to do calculations to get correct results and without them scientists cannot form theories
The prosecution offers a lab report prepared by a government chemist who examined a white powdery substance seized from a box at Mary's house. The report indicated that the chemist used standard procedures in the analysis of the white substance, and the chemist prepared the report in the ordinary course of business. The report reflects the chemist's conclusion that the substance contained methamphetamine. Write a few sentences characterizing the report as either testimonial or nontestimonial hearsay.
Answer: The report prepared is a nontestimonial hearsay.
Explanation:
The nontestimonial hearsay can be defined as the expert opinion or statement given casually and not for the purpose of keeping or considering it as record by the government agent or agency. Here the given conclusion provided by the chemical expert is an example of nontestimonial hearsay because it is not the output of experimental and analytical procedures instead it is a casual opinion. Testimonial hearsay include the evidences that are based on detailed and thorough analytic procedures.
C₂H₄O₂ + O₂ ➞ CO₂ + H₂O
Answer:
C2H4O2 + 2O2 ==> 2CO2 + 2H2O
Explanation:
Start with the carbons
C2H4O2 + O2 ==> 2CO2 + H2O There are 2 on the left, so you need 2 on the right.
Next deal with the hydrogens. You have 4 on the left so you have to make 4 on the right
C2H4O2 + O2 ==> 2CO2 + 2H2O
The oxygens are the real devil in this question. Be careful how you handle them. There are 2 * 2 = 4 from the CO2 and 2*1 = 2 from the water. The total is 6
Now you can't just put a 3 in front of the O2. There are 2 in the given chemical. So you don't need 6. You need 6 -2 = 4. But the oxygen is O2. You have to divide the 4 by 2 to get 2
C2H4O2 + 2O2 ==> 2CO2 + 2H2O
And that's your answer.
Give reasons: a) Cocoons are boiled in hot water. b) Camel wool considered a natural health product.
Answer:
•cocoons are boiled in hot water for obtaining silk fibres from cocoons.
•camel wool considered a natural health product because it has excellent thermal proities
Which idea behind the shape of molecules includes the concept that electrostatic repulsion between electron pairs surrounding an atom causes these pairs to be separated as far as possible
Answer:
VSEPR theory
Explanation:
The valence shell electron pair repulsion theory was propounded by Gillespie and Nylom (1957).
The entire idea of the VSEPR theory is that the shape of a molecule depends on the electrostatic repulsion between electron pairs surrounding the central atom in a molecule which causes these pairs to be separated as far as possible.
The shapes of many molecules can be accurately predicted based on this model.
which of the following pairs are ionic compounds ( Al,Cl),(Na,O),(Al,F)
Answer:
This answer I think it is Al,F
Ginger wanted to see how long it would take to get to Brownsville from Houston. If it is 570 kilometers (km) to Brownsville, how long would it take her if she could only drive an average speed of 60 km/hour
Answer:
9.5 hours/ 9 hours 30 mins
Explanation:
Distance = speed × time so
Time = Distance ÷ speed
= 570 ÷ 60
= 9.5 hours
plant growth is chemical change or physical change
Answer:
its a chemical change.
hope it helps.
stay safe healthy and happy...Answer: it is a chemical change because it involves chemical process
Explanation:
How are the boiling point and freezing point of a solvent affected when a solute is added?
Both the boiling point and the freezing point decrease.
Both the boiling point and the freezing point increase.
The boiling point increases, and the freezing point decreases.
The boiling point decreases, and the freezing point increases.
Answer:
this can helps you know the answer
Answer:
C.) The boiling point increases, and the freezing point decreases.
Explanation:
In which of the following will the density increase?
Group of answer choices
An iron bar is heated.
A lead weight is moved from sea level to the top of a high mountain.
A sample of water is frozen.
A diamond is submerged in water.
A sample of chlorine gas is compressed.
Fe-54 = 5.845%
Fe-56 = 91.754%
Fe-58 = 2.119%
(Please help)
Calculate the average atomic mass/ given their percent abundance
Answer:
55.768
Explanation:
The following information is given in this question:
Fe-54 = 5.845%
Fe-56 = 91.754%
Fe-58 = 2.119%
First, we convert from percentage abundance to decimal abundance
Fe-54 = 5.845% = 0.05845
Fe-56 = 91.754% = 0.91754
Fe-58 = 2.119% = 0.02119
To find the average atomic mass of iron (Fe), we multiply each isotopes' decimal abundance by its mass no and find the sum as follows:
Average atomic mass = (0.05845 × 54) + (0.91754 × 56) + (0.02119 × 58)
Average atomic mass = 3.1563 + 51.38224 + 1.22902
Average atomic mass = 55.768
The maximum number of electrons that can be present in an SHELL is
a) [tex]2 {n}^{2} [/tex]
b) [tex]2 {n}^{2} + 1[/tex]
c) 2n
d) none of these.
[tex]\huge\boxed{\fcolorbox{red}{blue}{ QUESTION }}[/tex]
The maximum number of electrons that can be present in an shell is
[tex] \orange{\underline{\huge{\bold{\textit{\green{\bf{OPTIONS}}}}}}} [/tex]
a) [tex]2 {n}^{2} [/tex]
b) [tex]2 {n}^{2} + 1[/tex]
c) 2n
d) none of these.
[tex] \huge\mathbb{\red A \pink{N}\purple{S} \blue{W} \orange{ER}}[/tex]
OPTION (a)
[tex]2 {n}^{2} [/tex]
[tex] \bold { \red{ \star{ \blue{EXAMPLES}}}}[/tex]
In First shell only 2 electron can be placed .
[tex]2 {n}^{2} \\ n = 1 \: (bez \: \: no \: \: shell \: = 1) \\ so \\ 2 { n}^{2} = 2 \times {1}^{2} = 2 \: electrons[/tex]
In second shell 8 electrons can be placed
[tex]2 {n}^{2} \\ n = 1(bez \: \: no\: \: shell \: = 2) \\ 2 {n}^{2} = 2 \times {2}^{2} = 2 \times 4 = 8 \: electrons[/tex]
Which of the following is a base? (3 points)
AgO
Ca(OH)2
HF
NaCl
Answer:
Ca(OH)2 is base
is answer of this question
hope this will help you more
Answer:
Ca(OH)2
Explanation:
Got it right on the test
SI units is an improved version of MKS system.
Answer:
the S.I unit
Explanation:
is the best unite
(Please Help)
1.What is the most common isotope for element X
2.Calculate the average atomic mass or element X
Answer:
1. Isotope 2 occurs most commonly
2. 39.02amu
Explanation:
1. Isotope 2 has a relative abundance of 78.68% i.e. 78.68 out of 100, hence, it is the isotope that occurs most commonly.
2. Isotope 1 = 9.67%, mass no: 38
Isotope 2 = 78.68%, mass no: 39
Isotope 3 = 11.34%, mass no: 40
Isotope 4 = 0.31%, mass no: 41
To find the average atomic mass of element X, we multiply each isotopes' relative abundance by its mass no and find the sum as follows:
We convert each percentage to decimal abundance:
Isotope 1 = 9.67% = 0.0967
Isotope 2 = 78.68% = 0.7868
Isotope 3 = 11.34% = 0.1134
Isotope 4 = 0.31% = 0.0031
(0.0967 × 38) + (0.7868 × 39) + (0.1134 × 40) + (0.0031 × 41)
3.6746 + 30.6852 + 4.536 + 0.1271
Average atomic mass = 39.02amu
In an electrically neutral atom, the number of
protons equals the number of neutrons.
protons equals the number of electrons.
neutrons equals the number of electrons.
A. Protons equals the number of neutrons
B. Protons equal the number of electrons
C. Neutrons equals the number of electrons
Answer: B
Answer:
B
Explanation:
because protons have a +1 charge and electrons have a -1 charge, so if an atom is neutral it must have the same amount of protons and neutrons
NEED AN ANSWER ASAP!!! PLSSS
Compare and contrast an electrolytic cell with a voltaic cell. Provide one example where both are present in daily life.
Answer:
In both voltaic and electrolytic cells, oxidation occurs at the anode, while reduction occurs at the cathode. Thus, both these cells exhibit redox reactions. In both these cells, electrons flow from the anode to the cathode through the externally connected conductor.
Answer:
ELECTROLYTIC CELL
An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.
EXAMPLE
Nelsons cell and Downs cell
VOLTAIC CELL OR GALVANIC CELL
The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.
EXAMPLE
Daniel cell
Explanation:
3. How many moles are present in 100 g of Ca(NO3)2?
PLEASEEE HELP ASAPP
0Answer: 0.6094
Explanation:
no of moles = mass / molar mass = 100/164.088= 0.6094 mole
Answer:
0.609 moles
Explanation:
mass in g ÷ atomic mass = moles
Ca(NO₃)₂ = 1 Ca 40.078 amu
2 N 28.0134 amu
+ 6 O 95.994 amu
____________________
164.0854 amu
100 g ÷ 164.0854 amu = 0.609 moles
three significant digits
If the sky is actually black, and the water is actually clear, where does the blue color for the sky and water come from?
Answer:
that the water is blue because of the way water absorbs light, the way particles in the water scatter light, and also because some of the blue light from the sky is reflected
An empirical research method in which data are gathered from observations of phenomena, hypothesis are formulated and tested, and conclusions are drawn that validate or modify the original hypothesis is known as the: Group of answer choices Gotham theory Scientific Method Niels-Bohr hypothesis Entropy theory
Answer:
Scientific Method
Explanation:
Science is empirical in nature. The entire purpose of science is to discover new knowledge.
The empirical research method in science all begins with gathering observations from phenomena. After that, the researcher formulates appropriate hypothesis which are rigorously tested.
The conclusions drawn from testing the original hypothesis validate or modify the original hypothesis.
a) The bubbles must be negatively charged.
b) The bubbles must be positively charged.
c) The bubbles must have the opposite charge to the charge on the student.
d) The bubbles must have the same charge as the charge on the student.
Answer:
C
Explanation:
like charges repel each others so if they have the same charge they will move away from each other
1. All of the following statements are true
regarding spontaneous process, EXCEPT:
A. It occurs without requiring an outside
force.
B. It can be a physical or chemical change
C. It will continue until equilibrium is
reached.
D. It will suddenly stop once products ar
formed.
Which of the following is an example of a
spontaneous process?
A. Melting of ice in room temperature
B. Transfer of heat from a cold objectt
hot object
C. Removing rust on an iron nail
D. Separation of hydrogen and oxygen
atoms via electrolysis
Answer:
ïgGshdhdhdhdhdbdhdhdjddk
How to work out the amount of carbon dioxide that is released when fully combusted with 4kg of ethanol?
Answer:
There is 7642 grams of CO2 released
Explanation:
Step 1: Data given
carbon dioxide = CO2
Molar mass of carbon dioxide = 44.01 g/mol
Mass of ethanol = 4 kg = 4000 grams
Molar mass of ethanol = 46.07 g/mol
Step 2: The reaction
Combustion of ethanol means there is oxygen (O2) added. The products are CO2 and H2O.
C2H5OH + 3O2 → 2CO2 + 3H2O
Step 3: Calculate number of moles of ethanol
Moles ethanol = mass ethanol / molar mass ethanol
Moles ethanol = 4000 grams / 46.07 g/mol
Moles ethanol = 86.82 moles
Step 4: Calculate number of moles CO2
For 1 mol ethanol we need 3 moles to produce 2 moles CO2 and 3 moles H2O
For 86.82 moles of ethanol we'll have 2*86.82 = 173.64 moles CO2
Step 5: Calculate mass of CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 173.64 moles * 44.01 g/mol
Mass CO2 = 7642 grams
There is 7642 grams of CO2 released