Answer:
tempature of the person, check carbon levels in the house or place where the person is.
Explanation:
The chemical weathering of feldspar produces _____.
Answer:
The chemical weathering of feldspar produces clay minerals
Explanation:
clay minerals form in the presence of water.
Help me pls!
What is heliuim?
Answer:
it's a chemical Element
Explanation:
symbol He
atomic number 2.
In an endothermic reaction, a drop in temperature would be observed. TRUE FALSE
Explanation:
If the reaction is endothermic as written, an increase in temperature will cause the forward reaction to occur
As defined by Aristotle, which one of the following is an element?
1. water 2. air 3. soil 4. none of them
Answer:
4
Explanation:
none of them
they are compounds and mixtures
Answer:
4. none of them
Explanation:
Water is a compound.
Air is a mixture.
Soil is a mixture.
None of them are elements.
Which quantity can be calculated using the equation E=MC^2
Answer:
The energy needed to split an atom into separate protons, neutrons, and electrons
Explanation:
The equation E = MC^2 is developed by Einstein’s Special Relativity Theory
where,
E = Energy
M = mass
C = speed of the light
The energy should be measured in Joules i.e J
The mass should be measured in Kilogram i.e Kg
And, the speed of the light should be measured in meters per second i.e ms-1
The C should be squared
Now the energy is required to divided into three particles i.e protons, electrons and neutrons
It also needs to allocate the nucleus into distinct protons and neutrons that we called binding energy of nuclear
And if the energy is required to take off an electron from an atom we called the energy of ionization
And if the energy is required to add an electron to an atom so we called it affinity of electron
how many different d orbits are within the 3d sublevel
Answer:
Its 5
Explanation:
An isotope of lead can be represented by the following symbol ²⁰⁷ 82 PB. From this symbol, it can be deduced that one atom of the isotope has: A) 82 neutrons B) 82 protons C) 125 protons D) 207 protons
Answer:
B) 82 protons
Explanation:
The number of protons for an element never change. 82 Is the atomic number for Pb which is how many protons it has. An isotope means it has more neutrons.
what is the valency of hydroxide
Answer:
Its valancy is 1.
As it has the formula OH-.
It has valancy 1.
hope it helps..
how many moles are in 8.5 x 10^25 molecules of CO2
Answer:
the answer is 5.1 1049 mol.
25g ice crystals are taken in a beaker and inserted a thermo meter into it and slowly heated. Answer the following questions based on the above experiment.
a) At what temperature ice starts melting?
b) At 50 0 C is reached, what is the physical state of ice?
c) At 100 0 C is reached the boiling point of substance is not rising for some time. What is the reason for it?
d) What is the boiling point of the substance?
e) What is physical state of the substance above 100 degree C?
Answer:
a) 0°C
b) liquid
c) The energy supplied at 100°C is utilized in breaking the intermolecular forces in the liquid.
d) 100°C
e) gas
Explanation:
There are three States of matter; solid, liquid and gas. If we start heating 25g of ice in a beaker with a thermometer inserted into it, the ice will change from solid to liquid and finally to gas as the temperature increases.
At 0°C, the solid ice begins to melt and remains liquid between 0°C-100°C. This is called the liquid range of water. At 100°C, the heat supplied does not lead to further rise in temperature. The energy supplied is rather utilized in breaking the intermolecular forces in the liquid. This is known as the latent heat of vaporization. Above 100°C, the liquid is changed to vapour. Water vapour is commonly called steam.
Plz solve mcqs#04 with full detailed.note
Answer:
The correct option is;
(B) 1 s², 2s², 2p⁶, 3s², 3p³
Explanation:
The electron configuration is the outline of the electron arrangement about a nucleus
In the systemic pattern of electron arrangement within an atom, there are, s, p, d, f orbitals
The maximum number of electrons in an s, p and d orbital = 2, 6, and 10 respectively
Based on Aufbau's principle the electrons are arranged based on the order of their energy level
The charge is presented by the number of electrons in the outermost shell, an element able to form an ion of charge of -3 will gain 3 electrons to complete its outermost shell
Among the options given, option B is the only option that has the capacity to take the electrons to complete the number of electrons in the p orbital outermost shell to 6 from 3, that is 3p³ + 3e⁻→ 3p⁶.
URGENT:
Do you switch charges for ionic or covalent bonds when naming them?
Answer:
ionic
Explanation:
Calculate mole fraction of ethylene
Glycol in solution
containing 20% g C2H6O2 by mass.
Answer:
Explanation:
20% of C2H6O2
since its a solution, this means that it has 20g of ethylene glycol and the rest is water.
Molar mass of C2H6O2 = (12 x 2) + (1 x 6) + (2 x 16)
= 62
mole = mass/molar mass
Moles of C2H6O2 = 20/62
= 0.322 mol
Moles of water = 80/18
= 4.444 mol
mole fraction = mol of solute / tatal mol of solution
Mole fraction of ethylene glycol = 0.322/(0.322 + 4.444)
= 0.068
Mole fraction of water = 1 - 0.068
= 0.932
The electron configurations of two unknown elements x and y are shown. X: 1s2 2s2 2p6 Y: 1s2 2s2 2p6 3s2 3p6 Which statement is most likely correct about the two elements? A) They will react because X can give up two electrons B) They will react because X and Y can share two pairs of electrons to become stable C) They will not react because both have a complete outermost shell and are stable D) They will not react because both will give up one electron. to become stable.
Answer:
B) They will react because X and Y can share two pairs of electrons to become stable
Explanation:
The electron configurations of two elements x and y are given :
X: 1s2 2s2 2p6
Y: 1s2 2s2 2p6 3s2 3p6
The statement that is true for both the elements is that, they both will react as they both can share two pairs of electrons to become stable.
To become stable the outermost shell or p orbital should have 8 electrons, so element X can gain 2 atoms to become stable.
Element Y can also react as it can also share two atoms to fulfill its 3p orbital and will stable.
Hence, the correct option is "B".
25. Which answer best describes the continental rise? area of land that drops toward deep ocean basins 75 mile shallow flat area just off coastlines thick deposits of sediments carried off of the shelf the surf area along coastlines
Answer:
Thick deposits of sediments carried off of the shelf
Explanation:
The continental rise is a thick deposit of sediments that accumulate between the continental slope and the abyssal plain
A is wrong. The area of land that drops toward the deep ocean basins is the continental slope.
B is wrong. The 75-mile shallow flat area just off coastlines is the continental shelf.
D is wrong. The surf area along coastlines is the surf zone .
Which of the following is the best explanation for why it is important to follow lab safety guidelines
a. Following laboratory safety guidelines prevents all lab accidents.
b. Following laboratory safety guidelines minimizes the chance of lab ac
C. Following laboratory safety guidelines prevents fires.
d. Following laboratory safety guidelines allows quick response during la
Please select the best answer from the choices provided
Answer:
B
Explanation:
The main aim of lab rules is to minimize the no of accidents
Calculate the pH of a solution obtained by mixing 477 mL of 0.17 M hydrochloric acid with 253 mL of M lithium hydroxide. Assume the combined volume is the sum of the two original volumes.
Answer:
pH = 0.984
Explanation:
Molarity LiOH = 2.1x10⁻²M
HCl will react with LiOH as follows:
HCl + LiOH → H₂O + LiCl
1 moles of HCl reacts per mole of LiOH
Moles of each reactant in solution are:
HCl = 0.477L ₓ (0.17mol / L) = 0.08109 moles HCl
LiOH = 0.253L ₓ (2.1x10⁻² mol / L) = 5.313x10⁻³ moles of LiOH.
That means LiOH is the limiting reactant and excess moles of HCl that will remain in solution are:
0.08109 mol - 0.005313mol = 0.0758 moles HCl
As HCl dissociates in water as H⁺ and Cl⁻ ions, you will have in solution 0.0758 moles of H⁺
pH = -log [H⁺] and [H⁺] = moles H⁺ / L of solution.
Volume of the mixture in liters is: 0.477L + 0.253L = 0.730L.
That means [H⁺] is 0.0758 moles of H⁺ / 0.730L = 0.1038M
Replacing:
pH = -log [H⁺]
pH = -log [0.1038]
pH = 0.984A stone bead and an iron bead are dropped into a cup of water. They both sink to the bottom of the cup. What can be said about these beads?Immersive Reader
Answer:
Both have densities greater than that of water
Explanation:
The ability of objects to either float or sink in a liquid depends on their relative densities.
If an object is denser than a liquid it will completely sink in it, but if the density of the object is less than that of the liquid, it will sink until the weight of liquid displaced is equal to the weight of the object, then it will finally float in that liquid.
In the case of the stone bead and iron beads dropped into a cup of water, hey both sank to the bottom because they are denser than water.
What were the defects in Rutherford’s atomic model and how were these removed by Bohr?
Adrian loves the pancakes! The problem is, the recipe serves only six, and he has 540 people in his family (including aunts, uncles, and cousins). Now, he needs help increasing the recipe to feed his entire family. However, Adrian is particular - he insists on using only three significant figures with scientific notation.
Answer:
ingredient. U.s unit. SI unit. SI unit(540)
flour. 2cups. ²/6. 180cups = 1.8×10²
milk. 2cups. ²/6. 180cups. =1.8×10²
eggs. 2. ²/6. 180eggs. =1.8×10²
melted butter. ⅓cup ¹/18. 30cups. =3×10¹
sugar. 1spoon. ¹/6. 90spoons. =9×10¹
baking powder 2spoons ²/6. 180spoons. =1.8×10²
salt. ½spoon. ¹/12. 45spoons. =4.5×10¹
Explanation:
1) to get the SI unit divide the U.S unit by 6
example:eggs = 2÷6. =²/6
2) to get the SI unit for 540 people ,multiply the SI unit by 540.
example:eggs ²/6×540. = 180
3)convert the answers to scientific notation
example:eggs =180. =1.8×10²
PLEASE HELP A woman travels to Canada where milk is sold in liters. She wants to buy enough milk at the grocery store to last 5 days and she knows at home she uses 0.75 gallons per week. How many liters must she buy?
Answer:
About 2 liters
Explanation:
Since 1 gallon equals 3.785 liters, you figure out how many liters per week she uses by 3.785 x 0.75 which is 2.83875. Then divide that by 7 which is 0.405535 liters per day. Then multiply that by 5 days which is 2.027 liters in 5 days.
Answer the following questions:
1. Define a compound. State three points of evidence to show that sodium chloride is a compound.
2. When Iron powder and Sulphur powder were mixed together and heated strongly, a substance A was formed. When did. Hydrochloric acid was added to substance A, the gas B was evolved.
a) What is A and what type of substance is it?
b) Name the gas B. State one characteristic property of gas B.
c)Is the reaction of Iron and Sulphur powder a chemical change or a physical change.
Answer the question according to the class 9th student.
Answer:
1. A compound is a group of elements that cannot be separated by physical methods.
NaCl is a compound becuse it cannot be separated by physical methods.
It consists of postive and negative ions.
It can be separated only by chemical reactions.
2. (a) A is a mixture of iron and sulphur and it is in liq form.
(b) Gas B is hydrogen gas and it has sharp pungent irritating smell.
(c) It is a physical change.
Explanation:
What do we call matter made you of only one kind of atom?
And Atoms have weight and take up space
Answer:
Matter is any substance, if it is made up of only one kind of atom, then it is an element. Elements consists of atoms with the same weight and same number of protons in the nuclei.
The activation energy (E*) for 2N2O ---> 2N2 + O2 is 250 KJ. If the k for this reaction is 0.380/M at 1001oK, what will k be at 298oK? What will the half-life be at both temperatures?
Answer:
Explanation:
GIven that:
The activation energy = 250 kJ
k₁ = 0.380 /M
k₂ = ???
Initial temperature [tex]T_1 =[/tex] 1001 K
Final temperature [tex]T_2 =[/tex] 298 K
Applying the equation of Arrhenius theory.
[tex]In \dfrac{k_2}{k_1 }= \dfrac{Ea}{R}( \dfrac{1}{T_1 }- \dfrac{1}{T_2})[/tex]
where ;
R gas constant = 8.314 J/K/mol
[tex]In \dfrac{k_2}{0.380 }= \dfrac{250 * 10^3}{8,314}( \dfrac{1}{1001 }- \dfrac{1}{298})[/tex]
[tex]In \dfrac{k_2}{0.380 }= -70.8655[/tex]
[tex]\dfrac{k_2}{0.380 }= e^{-70.8655}[/tex]
[tex]\dfrac{k_2}{0.380 }= 1.67303256 \times 10^{-31}[/tex]
[tex]{k_2}= 1.67303256 \times 10^{-31} \times {0.380 }[/tex]
[tex]{k_2}= 6.3575 \times 10^{-32}[/tex] /M .sec
Half life:
At 1001 K.
[tex]t_{1/2} = \dfrac{In_2}{k_1}[/tex]
[tex]t_{1/2} = \dfrac{0.693}{0.38}[/tex]
[tex]t_{1/2} =[/tex] 1.82368 secc
At 298 K:
[tex]t_{1/2} = \dfrac{0.693}{6.3575 \times 10^{-32}}[/tex]
[tex]t_{1/2} =1.09 \times 10^{31} \ sec[/tex]
suppose a 22.092 g sample of 1 1 mixture of acetylferrocene and ferrocene was sepeerated by column chromatography and the recovered fractions weighed 9.017 g acetylferrocene and 8.075 g ferrocene what was the eprcent recovery of acetyl ferrocene
Answer:
Percentage recovery of acetylferrocene = 81.6%
Explanation:
Mass of the sample mixture = 22.092 g
Ratio of mixture of acetylferrocene and ferrocene = 1 : 1
This means that the sample conatains equal amounts of acetylferrocene and ferrocene.
Therefore the mass of each sample in the mixture = 22.092 g / 2 = 11.046 g
Mass of acetylferrocene recovered = 9.017 g
Percentage recovery of acetylferrocene = (mass of recovered/ mass in sample) * 100%
Percentage recovery of acetylferrocene = (9.017 g / 11.046 g) *100%
Percentage recovery of acetylferrocene = 81.6%
During which two minute time period is the temperature of the water changing fastest? Select one: a. 0-2 minutes b. 2-4 minutes c. 4-6 minutes d. 6-8 minutes Clear my choice
Answer:
b. 2-4
Explanation:
Look at the slope of the line, between 0-2 and 4-6 the slope is only 10, but between 2-4 the slope is 20, so that's when the temperature is changing the fastest. In the same time it took for the water to increase by 20 degrees between 0-2 and 4-6, the temperature of the water increased by 40 degrees between 2-4 so that's when the change is the fastest.
Characteristic 1: a scar due to an injury
Characteristic 2: the shape of a person's face
Which characteristic is a trait that can be inherited? Explain your answer.
Answer:
Only characteristics that are coded for by genes can be inherited. The shape of a person's face is inherited because this characteristic is coded for by genes. Characteristics that are due to environmental factors cannot be inherited. A scar due to an injury cannot be inherited because this characteristic is a result of an environmental factor.
Explanation:
sample response
please what
is combustion
Answer:
when the coal is heat with presence of oxygen it's called combustion...
The fact that a heat pump requires energy to move heat from a colder object (the outside of a house) to a hotter object (the inside of the house) is a real life observation of which thermodynamic law?
Answer:
The correct answer is - the second law of thermodynamics.
Explanation:
The second law of thermodynamics says that the in all heat energy exchange or transfer, and if there is no gain or lose of energy in a system, the potential energy of the particular state in that system will less than that of initial state of the system in any case.
It also suggests that the processes deals with the conversion of the heat energy are irreversible and the energy can be transfer from lower temperature system to higher temperate system without adding energy.
Thus, The fact that a heat pump requires energy to move heat from a colder object to a hotter object is a real life example of the second law of thermodynamics.
Calculate the pOH and pH of a solution which contains 0.001 M NaOH. Assume 100% ionization. (Need an in-depth explanation with formulas please)
Answer:
pH: 11
pOH: 3
Explanation:
NaOH is a strong base which means that it dissociates completely in water. It will break apart into Na⁺ and OH⁻ ions.
NaOH ⇒ Na⁺ + OH⁻
Because NaOH dissociates completely into its respective ions in water, the moles of NaOH is equal to the moles of hydroxide ions. So, [OH⁻] = 0.001 M.
Now to find the pOH, use the formula pOH = -log[OH⁻].
pOH = -log[OH⁻]
= -log(0.001)
= 3
The pOH of the solution is 3.
To find the pH, subtract the pOH from 14 since pH + pOH = 14.
14 - 3 = 11
The pH of the solution is 11.
Hope that helps.