Which of the following is a trait of group 18 (column 18)?
they are all stable metals
They are chemically stable gasses
They are all reactive
metals
They are a mix of reactive gasses and solids
Answer: They are chemically stable gases
Explanation:
Group 18 is also called the noble gases - because they have full valence shells it means they are stable and won't chemically react.
10.0 gram sample of H20(l) at 23.0°C absorbs. 209 joules of heat. What is the final temperature of H20(l) sample?
What are “condensation nuclei”?
Answer:
Cloud condensation nuclei or CCNs are small particles typically 0.2 µm, or 1/100 the size of a cloud droplet on which water vapor condenses. Water requires a non-gaseous surface to make the transition from a vapour to a liquid; this process is called condensation.
Which element has four energy levels?
cesium (Cs)
rubidium (Rb)
potassium (K)
sodium (Na)
Answer:
Potassium (K)
Explanation:
Out of the four options, Potassium is the only one to fill a total of 4 energy levels.
Both Cesium (Cs) and Rubidium (Rb) fill more than three energy levels, with Cesium filling 6 and Rubidium filling 5.
Sodium (Na) only fills 3 energy levels.
Thus, that leaves Potassium (K), which has 4 energy levels.
Hope this helped ^-^
i need help on question 3 true or false thxxx quick i’m timed
Answer:
The answer is true.
1)26.4 % Carbon
3.3 % Hydrogen
70.3 % Oxygen
Molar Mass: 91.0 g/mol
Empirical Formula:
Molecular Formula:
Answer:
1. Empirical formula => CH2O2
2. Molecular formula => C2H4O4
Explanation:
From the question given above, the following data were obtained:
Carbon (C) = 26.4 %
Hydrogen (H) = 3.3 %
Oxygen (O) = 70.3 %
Molar mass of compound = 91.0 g/mol
Empirical formula =..?
Molecular formula =..?
1. Determination of the empirical formula of the compound.
C = 26.4 %
H = 3.3 %
O = 70.3 %
Divide by their molar mass
C = 26.4 /12 = 2.2
H = 3.3 /1 = 3.3
O = 70.3 /16 = 4.39
Divide by the smallest
C = 2.2 /2.2 = 1
H = 3.3 /2.2 = 2
O = 4.39 /2.2 = 2
Empirical formula => CH2O2
2. Determination of the molecular formula of the compound.
Molar mass of compound = 91.0 g/mol
Empirical formula => CH2O2
Molecular formula => [CH2O2]n
We shall determine the value of n as follow:
[CH2O2]n = 91
[12 + (2×1) + (2×16)]n = 91
[12 + 2 + 32]n = 91
46n = 91
Divide both side by 46
n = 91/46
n = 2
Molecular formula => [CH2O2]n
Molecular formula => C2H4O4
In the given case where 26.4 % Carbon , 3.3 % Hydrogen , 70.3 % Oxygen , and Molar Mass: 91.0 g/mol the:
Empirical Formula: [tex]C_2H_3O_4[/tex] Molecular Formula: ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]Given:
Carbon (C) = 26.4 %
Hydrogen (H) = 3.3 %
Oxygen (O) = 70.3 %
Molar mass of compound = 91.0 g/mol
Determination of the empirical formula of the compound:-
Divide by their molar mass for obtaining moles: C = 26.4 /12 = 2.2 H = 3.3 /1 = 3.3 O = 70.3 /16 = 4.39 for ratio Divide by the smallest: C = 2.2 /2.2 = 1 H = 3.3 /2.2 = 1.5 O = 4.39 /2.2 = 2
The ratio is CHO = 1 : 1.5 : 2
multiply with 2 to find correct and complete number ratio
C = 1 × 2 = 2
H = 1.5 × 2 = 3
O = 2 × 2 = 4
Thus, the Empirical formula => [tex]C_2H_3O_4[/tex]
Mass × n = molar mass
12 × 2 + 1 × 3 + 16 × 4 = 91
24 + 3 + 64 = 91
91 = 91
Thus moles are 1 which means
molecular formula = ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]
Thus, here in the given data:
Empirical Formula: [tex]C_2H_3O_4[/tex]Molecular Formula: ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]
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https://brainly.com/question/15960587
Which organelle provides a protective covering to the cell and controls what enters and leaves?
Cell Membrane. Has multiple proteins between it that allow certain things in and out. I think.
Will give brainliest!!!
How is coal formed?
Answer:
Coal is formed when dead plant matter submerged in swamp environments is subjected to the geological forces of heat and pressure over hundreds of millions of years. Over time, the plant matter transforms from moist, low-carbon peat, to coal, an energy- and carbon-dense black or brownish-black sedimentary rock.
What type of kinetic energy is a rainbow?
What organisms are not able to photosynthesize?
A. Grasses
B. Rabbits
C. Algae
D. Some bacteris
Answer:
B. Rabbits
For photosynthesis you need chlorophyll but rabbits don't have it.
Which of the following statements about photosynthesis is true?
A. Plants release CO2 into the atmosphere.
B. Plants take in CO2, then use the carbon (C) to make sugar.
C. Plants only do photosynthesis when they are hungry.
D. None of the above
A chemical change always involves...
A. a color change
B. a change in shape
C. the state of matter changing
D. a new substance forming
I need help ASAP... look at the picture:)
Answer:
its definitely A
Explanation:
hope this helps
Select all that apply.
How would you compare Venus's rotation to Earth's rotation?
Venus's rotation is backward compared to Earth's.
Venus's rotation is the opposite compared to Earth's.
Venus's rotation is retrograde compared to Earth's.
Venus's rotation is the same compared to Earth's.
I need answers ASAP
Answer:
backward, opposite, retrograde
Explanation:
why, i just got it right when i put that.
Answer:
here they are
Explanation:
Venus's rotation is backward compared to Earth's.
Venus's rotation is the opposite compared to Earth's.
Venus's rotation is retrograde compared to Earth's.
Which one of these have the biggest ionization energy and why? O, N, F
Answer: Fluorine has the highest ionization enthalpy.
Explanation: This is because the ionization energy decreases from top to bottom and increases from left to right. Also, ionization enthalpy is the amount of energy required by an isolated gaseous atom to lose an electron in its ground state.
Since fluorine needs just one atom to attain noble gas configuration so it will not want to lose any electron and hence a high amount of energy will be required to remove an electron from it.
compare and contrast a Covalent and an ionic bond
What would be my conclusion for the question How much salt will it take to make an egg float.
Answer:
adding 3 tbsp. of salt should be about enough to make the egg float.
Explanation:
The density of the average egg will be slightly greater than that of water, so it will sink. To make the egg float, we have to make the water more dense by adding salt. For 1 cup of water.
HELP ME NOW ASAP PLEASE, 10 POINTS HURRY
A geologist is making observations from atop a small mountain. She sees two parallel faults: one directly to the east and one directly to the west. She concludes that these faults are caused by tension stretching the crust. From what type of land feature is the geologist making her observations? plateau anticline syncline fault-block mountain
Answer: fault-block mountain
Explanation:
I got it right on edgen 2020
Answer:
d fault-block mountain
Explanation:
what are units of molarity
Answer:The units of molarity are M or mol/L. A 1 M solution is said to be “one molar.”
Explanation:
Answer:
mol/L
Explanation:
The chemical equation below shows the reaction of methane (CH4) and oxygen gas (O2) to form carbon dioxide (CO2) and water (H2O).
CH4 + 2O2 → CO2 + 2H2O
In this equation, which of the following are products?
Answer:
CO2 + 2H2O
Explanation:
left side of the equation is the products side, right side is the reactant side
Answer:
Carbon Dioxide(CO2) and Water (H2O)
Explanation:
Whatever is on the right side of the equation is the products, the left side is the reactants.
What is the Molarity of volumetric flask 1
What is the Molarity of volumetric flask 2
The Molarity of volumetric flask 1 : 1.26 M
The Molarity of volumetric flask 2 : 0.06 M
Further explanationDilution is a process of decreasing the concentration of a solution by adding a number of solvents
Can be formulated
M₁V₁=M₂V₂
M₁ = Initial Molarity
V₁ = Initial volume
M₂ = Final Molarity (after dilution)
V₂ = Final volume (after dilution)
Volume of volumetric flask = 500 ml
flask 1[tex]\tt M_1.V_1=M_2V_2\\\\9\times 0.07=M_2.0.5\rightarrow M_2=1.26[/tex]
flask 2[tex]\tt M_1.V_1=M_2V_2\\\\1.26\times 0.023=M_2\times 0.5\rightarrow M_2=0.06[/tex]
A. Stamens (p) The portion of the pistil receiving the pollen
B. Filament (q) The female structure of a flower
C. Pistil (r) The stalk of an anther
D. Stigma (s) The male part of a flower
D. Stigma (s) The male part of a flower
1-A→(s); B→(r); C→(q); D→(p)
2-A→(s); B→(q); C→(r); D→(p)
3-A→(r); B→(s); C→(p); D→(q)
4-A→(q); B→(r); C→(s); D→(p)
answer please 30pts
Answer:
(A) A-(S) ; B-(R) ; C-(Q) ; D-(P).
Explanation:
(A)-S_ The male part of a flower.
(B)-R _The stalk of an anther.
(C)-Q_ The female structure of a flower.
(D)-P _The portion of the pistil recieving the pollen.
The electron that is located in the outermost shell of the octet rule.
Answer:
im not sure what answer you're looking for here, their called valence electrons if thats what you're looking for.
Explanation:
Neutrons released in a fission reaction can strike other nuclei and cause
Answer:
Chain reaction
Explanation:
What is the concentration of H3O+ ions in saliva if [OH-] = 4.22 x 10-10 M? Provide the pH and the classification of this sample of saliva.
pH=4.625
The classification of this sample of saliva : acid
Further explanationThe water equilibrium constant (Kw) is the product of concentration
the ions:
Kw = [H₃O⁺] [OH⁻]
Kw value at 25° C = 10⁻¹⁴
It is known [OH-] = 4.22 x 10⁻¹⁰ M
then the concentration of H₃O⁺:
[tex]\tt 10^{-14}=4.22\times 10^{-10}\times [H_3O^+]\\\\(H_3O^+]=\dfrac{10^{-14}}{4.22\times 10^{-10}}=2.37\times 10^{-5}[/tex]
pH=-log[H₃O⁺][tex]\tt pH=5-log~2.37=4.625[/tex]
Saliva⇒acid(pH<7)
What is the wavelength of gamma ray electromagnetic radiation with a frequency of 2.73x10^20 Hz?
Answer:
1.10 × 10⁻¹² m
General Formulas and Concepts:
Chemistry - Atomic Structure
Speed of Light = Wavelength times Frequency
c = λν c = 3.0 × 10⁸ m/sExplanation:
Step 1: Define
ν = 2.73 × 10²⁰ Hz
Step 2: Find wavelength
3.0 × 10⁸ m/s = λ(2.73 × 10²⁰ Hz)
λ = 1.0989 × 10⁻¹² m
Step 3: Check
We are given 3 sig figs. Follow sig fig rules.
1.0989 × 10⁻¹² m ≈ 1.10 × 10⁻¹² m
Prokaryotic cells and Eukaryotic cells both contain all 4 biomolecules. True or False
Which of the following landforms (physical features) was formed when two landmasses collided?
Hawaiian Islands
Mariana Trench
Himalayan Mountains
explain why solid sodium chloride does not conduct electricity
Answer:
It does not contain free mobile ions
Explanation:
Solid sodium chloride does not conduct electricity because it does not contain free mobile ions.
Although sodium chloride is an ionic compound, in solid state, there is absence of free mobile ions. In aqueous solutions or in molten form, ionic compounds can conduct an electric current using free mobile ions as carriers. Therefore, they are electrolytes.In solid state ions are arranged into crystal lattice and will not conduct a current of electricity.