explain how temperature and mass affect the appearance of stars
Answer:
If the star has smaller mass than the Sun, it can fuse hydrogen into helium for at least a trillion years. The larger a star, the shorter its life because it fuses hydrogen into helium much more quickly. A star whose mass is more than 20 Suns will run out of hydrogen in only a few hundred million years.
What is the empirical formula of the following molecular formula: C3H6
Answer:
CH2
Explanation:
The empirical formula is the lowest ratio form of a compound. You can divide both C and H by 3 to get to CH2.
Calculate the heat energy released when 21.1 g of liquid mercury at 25.00 °C is converted to solid mercury at its melting point.
Constants for mercury at 1 atm
heat capacity of Hg(l) 28.0 J/(mol⋅K)
melting point 234.32 K
enthalpy of fusion 2.29 kJ/mol
There is a bottle of KCl solution: the volume is 35 mL; its molarity is 3.0 M.
After diluting it into final volume 200 mL, what is the molarity (in M) now?
Answer:
0.525 M
Explanation:
As the problem deals with a dilution process, we can use the following formula:
C₁V₁=C₂V₂Where subscript 1 stands for initial concentration and volume, while 2 stands for the final conditions. Meaning that in this case:
C₁ = 3.0 MV₁ = 35 mLC₂ = ?V₂ = 200 mLWe input the data given by the problem:
3.0 M * 35 mL = C₂ * 200 mLAnd solve for C₂:
C₂ = 0.525 M2) A balloon was inflated to a volume of 5.0 liters at a temperature of
7.0°C. It landed in an oven and was heated to 147°C. What is its new
volume?
Answer:
[tex]V_1=7.5L[/tex]
Explanation:
Hello there!
In this case, according to the Charles' law equation which help us to understand the directly proportional relationship between volume and temperature:
[tex]\frac{V_2}{T_2}= \frac{V_1}{T_1}[/tex]
Thus, by solving for the initial volume, V1, and making sure we use the temperatures in Kelvin, we can calculate the final volume as shown below:
[tex]V_1= \frac{V_2T_1}{T_2} \\\\V_1= \frac{5.0L*(147+273)K}{(7.0+273)K} \\\\V_1=7.5L[/tex]
Best regards!
Is anyone good at chemistry if so can someone help me please ?
(NO LINKS)
So, litmus paper is a qualitative tool for assessing the acidity or basicity of a substance (usually a solution). In general, blue litmus turns red in the presence of an acid, and red litmus turns blue in the presence of a base. They can't really tell you much more than that.
The solutions that are most likely acids are those that turn blue litmus red and do not evoke a color change in red litmus. A solution that turns red litmus blue or does not evoke a color change in blue litmus is likely not an acid. Using these criteria, solutions 4 and 7 are most likely acids since they both turn blue litmus red (and they cause no color change in red litmus).
The correct answer choice would thus be D.
Which of these actions is an example of erosion caused by gravity?
A.
Constant freezing and thawing water forming a hole in an asphalt road
B.
Pieces of rock breaking off and falling from a mountain top
C.
Chemicals in the air dissolve minerals in a marble statue
D.
Plant roots widening cracks in a large granite rock
Answer:
The answer is a
Explanation:because yes
Answer: The answer is B.
Explanation: The rocks falling off is caused by gravity. Other options don't include effects of gravity; Therefore, B is correct.
Calculate the OH-ion concentration of a 6.2x10-3 M HCIO3 solution.
Answer:
1.62x10⁻¹² M
Explanation:
HClO₃ is a strong acid, meaning that a 6.2x10⁻³ M solution has a molar concentration of H⁺ of 6.2x10⁻³.
With the above information in mind, we can calculate the pH of the solution:
pH = -log(6.2x10⁻³) = 2.21Now we can calculate the pOH of the solution, using the pH:
pOH = 14 - pHpOH = 11.79Finally we calculate [OH⁻], using the definition of pOH:
pOH = -log[OH⁻][OH⁻] = [tex]10^{-pOH}[/tex] = 1.62x10⁻¹² MMetals are cunductor of heat and electricity prove this statement
Answer:Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.
Explanation:
Which solution is a homogeneous mixture?
sand and water
salt and water
salad dressing
soil
Answer:
soil
Explanation:
Which of the following astronomical bodies would most likely be the largest?
1. A dwarf star from a nearby solar system
2. A comet
3. One of the gas giants in our solar system
4. Ganymede, the largest moon of Jupiter
Answer:
1
because a dwarf star will seemlarge because of the in ability of any human being to see d sun
An aluminum atom has 13 protons. If an atom of aluminum has a neutral charge, how many electrons should be moving around outside the nucleus?
Answer:
13
Explanation:
The correct answer is:
13
For an aluminum atom to have a neutral charge, 13 electrons must cancel out the positive charge from the 13 protons.
Pure substance uniform
Material use make car tyres and chewing gum?
Answer:
Rubber
Rubber
Make me brainlyist
a shape with five sides is called a?
Answer:
A five-sided shape is called a pentagon.
Explanation:
Answered by NONE other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO!!!
Hope this helped!!!
Answer:
a pentagon
Explanation:
I remember that a pentagon has 5 sides
HELP plis !
Find the molar masses of the following compounds: SHOW ALL WORK!!!
1) LiI. Li. 7 + I 127
134g/mol
2) PbCO4
Pb =. 1 x 207 =207
C = 1 X 12 = 12
O = 4 x 16 = 64
283 g/mol
3) Mg(OH)2
Mg= 1x 12 = 12
O= 2 x16 =32
H= 2x1= 2
46 g/mol
4) K3PO4
5) (NH4)3PO4
6) C12H22O11
7) Fe2(SO4)3
8) Na3P
9) AgF
10) NH4C2H3O2
Do these two points (equivalence point and titration endpoint) in a titration occur when the same volume of titrant has been added? please Explain.
Answer:
Show a picture
Explanation:
Think
about the physical properties used to identify elements as either metal,non-metals, or metalloids. Write
Imagine that you are asked to classify a group of elements as either metal, non-metals, or metalloids.
Explain how you would use their physical properties to accomplish this task.
Be sure to –Address the prompt, provide support, and conclude your thoughts. Write legibly and concisely.
Answer:
The elements can be classified as metals, nonmetals, or metalloids. ... Elements are further classified into metals, non-metals, and metalloids based on their properties, ... when they undergo chemical reactions They normally do not accept ... Most metal oxides are basic oxides and dissolve in water to form .
Explanation:
QUESTION 13
What is the boiling point of a 0.50 m aqueous solution of Al(NO 3) 3?
(The boiling point elevation constant for water is 0.512 °C/m.)
O a. 100.51 °c O b. 101.02 °c O C. 102.05 °C 0 d. 106.60 °C
Answer:
b. 101.02°C
Explanation:
The elevation of boiling point in a solvent due the addition of a solute is a colligative property called Boiling point Elevation. The formula is:
ΔT = Kb*m*i
Where ΔT is change in boiling point
Kb is boilinig point elevation constant = 0.512°C/m for water
m is molality of the solution = 0.50m
And i is Van't Hoff Factor (4 for the Al(NO₃)₃ because its disolution produce 4 ions)
Replacing:
ΔT = 0.512°C/m*0.50m*4
ΔT = 1.02°C
As the boiling point of pure water is 100°C and the increasing is of 1.02°C, boiling point of the solution is:
101.02°C
Right option is:
b. 101.02°C
17.4. A gas is found to have a density of 8.00 g/L. Find the volume of the gas in a balloon that
has a mass of 24 grams.
A. 192 liters
B. 3 liters
C. 0.3 liters
D. 32 liters
what is the answer?
Answer:
3 litersExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
We have
[tex]volume = \frac{24}{8} = 3 \\ [/tex]
We have the final answer as
3 litresHope this helps you
Check all that apply...helppppp
Answer:
dfgh
Explanation:
Answer that pls will give brainlist
Answer:
1. went on the first manned launch during the Apollo mission
2. responsible for all spacecraft systems
3. 4500 hour
4. published All-American Boys
5. Joined back in space organization as a consultant to inspire next generation for mars
3. When looking at a potential energy graph, how do you know if a reaction is
exothermic or endothermic?
Answer:
The correct answer is -
if the potential energy of reactants is less than the potential energy then it is an endothermic reaction and if the potential energy of reactants is more than the products it is an exothermic reaction.
Explanation:
The potential energy graph represents the energy change in a reaction as it progresses. In the initial part of the reaction, the energy shows are the energy of reactants that takes part in the reaction, and in the later phase, the energy has represented the energy of products of the reaction.
To find the reaction if it is endothermic or exothermic one can see if the potential energy is increased or decrease with the progress of the reaction. if the reaction is increasing in energy with the progress then it is endothermic and exothermic in less energy.
d. What do all of the molecules in the table have in common?
Answer:
They all have a certain amount of protons electrons and neutrons.
what is the molecular formula for a compound with the empirical formula: K2SO4 and a molecular mass of 696g
Answer:
K8S4O16 or K8(SO4)4 depending on if the SO4 is supposed to represent sulfate or not
Explanation:
Find the molar mass of K2SO4 first:
2K + S + 4O ≈ 174 g/mol
Divide the goal molar mass of 696 by the molar mass of the empirical formula:
696 / 174 = 4
This means you need to multiply everything in the empirical formula by 4:
K2SO4 --> K8S4O16 or K8(SO4)4 depending on if the SO4 is for sulfate or not
K₈S₄O₁₆ is the molecular formula for a compound with the empirical formula K₂SO₄ and a molecular mass of 696 g.
What is empirical formula?Empirical formula of a compound is defined as the simplest whole number ratio of atoms which are present in a compound.It does not make any mention of the arrangement of atoms or the number of atoms. The empirical formula gives information about the ratio of number of atoms which are present in a compound.
Molecular formula is determined from the empirical formula by dividing the molar mass of a compound by the empirical formula mass. The resultant which should be a whole number or very close to the whole number , then the subscripts are multiplied by the whole number to get the molecular formula.
In this case molar mass of K₂SO₄ that is 696 is divided by empirical formula mass which is 174.25 g which gives 4 , subscripts of K₂SO₄ is multiplied by 4 to give K₈S₄O₁₆ .
Thus, the molecular formula of compound is K₈S₄O₁₆.
Learn more about empirical formula,here:
https://brainly.com/question/14044066
#SPJ6
HI PLEASE HELP!!!!
7) As you move left to right across Period 3 from Sc to Zn, the energy needed to remove an electron from an atom —
A. generally increases
B. generally decreases
C. does not change
D. varies unpredictably
As we move left to right across Period 3 from Sc to Zn, the energy needed to remove an electron from an atom generally increases.
What is Periodic Table?Periodic table is the arrangement of chemical elements according to their atomic number in the tabular form. It is arranged from the lowest atomic number to highest atomic number i.e. the total number of protons in the atomic nucleus are in the increasing order.
In this type of recurring pattern which is called as periodic law in their properties in which elements in the same column (group) have similar properties.
The horizontal rows which goes from left to right is called as periods (7 in numbers) where the vertical columns which goes from up to down are called groups (18 in numbers). There is a square for each element includes a number and letters. These letter are the chemical name for the element like Hydrogen is H but for silver it is Ag. The number present is the atomic number. There are total 118 elements but only 94 is naturally exist on Earth.
So, as we move left to right across Period 3 from Sc to Zn, the energy needed to remove an electron from an atom generally increases.
Learn more about Periodic table, here:
https://brainly.com/question/11155928
#SPJ2
is pyramidal molecular geometry?
A. N2
B. H2O
C. NH3
D. CCL4
Answer:
[tex]\color{Blue}\huge\boxed{Question} [/tex]
Is pyramidal molecular geometry?[tex]\color{Blue}\huge\boxed{Answer} [/tex]
B.H2OAfter you compute the
of titrant
NaOH, you will copy that value into the row of the
data table for the
of analyte HCI.
Answer:
The first one is moles and so is the second one.
Explanation:
Answer:
1) Moles
2) Moles
Explanation:
On Edge
Ali says the climate of a town is rainy because it is raining outside today. Is she correct? In one or two sentences, explain why Ali is or is not correct about the climate of the town.
Answer:
Ali is incorrect.
Explanation:
Ali is wrong because the climate is a study of the weather pattern over a long period of time. You cannot look outside one day and determine the climate because the climate is long-term.
She could say the weather is rainy, because that is short term, but not the climate.
help me, please - i will make you brainliest
Answer:the correct answer is a.