Answer:
starts form from a accumulation of gas and dust ,which collapses due to gravity and starts to form stars
Answer:
Stars are the most widely recognized astronomical objects, and represent the most fundamental building blocks of galaxies. The age, distribution, and composition of the stars in a galaxy trace the history, dynamics, and evolution of that galaxy. Moreover, stars are responsible for the manufacture and distribution of heavy elements such as carbon, nitrogen, and oxygen, and their characteristics are intimately tied to the characteristics of the planetary systems that may coalesce about them. Consequently, the study of the birth, life, and death of stars is central to the field of astronomy.
How many meters in 500 km?
5,000
0.005
500,000
0.5000
Answer:
c i need 3 brainliests for virtuoso rank pls
Explanation:
Answer:
500,000 m
Explanation:
Each km has 1000m so to covert any km to m simply multiply the length value by 1000.
500 x 1000 = 500,000
If an element forms a 1- ion, in which group of the periodic table would you
expect to find it?
O A. 18
B. 2
C. 1
O D. 17
Answer:
D. 17
Explanation:
Halogens (group 17) are most likely to form a -1 ion. This is because they want to complete their octet. A prime example of this is sodium chloride. Sodium chloride is an ionic compound. Sodium gives up its valence electron, therefore, recieving a +1 charge, and Chlorine takes it, giving it a -1 charge. Chlorine is also in group 17, halogens.
Answer: the answer is D.17
Explanation:
Which statement describes copper?
O A. Copper is an insulator because its valence electrons can move freely from atom to atom.
O B. Copper is a conductor because its valence electrons can move freely from atom to atom.
O C. Copper is an insulator because its innermost electrons are shared between atoms.
O D. Copper is a conductor because its innermost electrons are shared between atoms.
Copper is a conductor because its valence electron can move freely from atom to atom. Option (B) is correct answer.
What is Insulator ?
Insulator is a material which does not conduct any current. Non metals are insulators. Electrons do not move freely in insulator. Thermal conductivity of insulator very is low and its resistance is vey high. These are used in making insulating electrical equipment.
What is Conductor ?Conductor is a substance which allow the electricity to flow through it. Metals are conductors. Electron can move freely in conductors. Thermal conductivity of conductor is very high and its resistance is vey low. These are used in making the electrical equipment.
Now let check all options one by one:
Option (A): Copper is a conductor not an insulator. Copper is a metal and it consists free electrons and electron can move freely from one atom to another atom.
So, option (A) is incorrect.
Option(B): Copper is a conductor because its valence electron can move freely from atom to atom. As copper is a metal it is a good conductor of electricity. The thermal and electrical conductivity of copper is high.
So, option (B) is correct.
Option (C): Copper is not an insulator it is conductor as already discussed in option (A).
So, option (C) is also incorrect.
Option (D): Copper is a conductor because its electron can move freely and it is a good thermal conductor.
So, option (D) is also incorrect.
Thus, from above conclusion we can say that Copper is a conductor because its valence electron can move freely from atom to atom.
Hence, option (B) is correct answer.
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When the head of a match burns, chemical reaction is taking place. But a certain amount of energy is required to get this reaction started. This is the reactions activation energy. Describe where this energy comes from. What provides this energy?
Answer:
Rubbing the match against a rough surface
The activation energy is provided by friction between surfaces
Explanation:
Activation energy is the energy required to start a chemical reaction. It is the minimum energy that must be supplied for a reaction to proceed.
When we strike a match against a rough surface, what we are trying to do is to supply the required activation energy in the form of friction in order to get the combustion reaction started.
Hence, the activation energy for the combustion of a match head is supplied by friction when the match head is struck against a rough surface.
What are the coefficients that will balance the skeleton equation below?
N, + H2
H NH3
1, 1, 2
3, 1, 2
1, 3,2
1, 3,3
Answer:
the answer is 1,3,2
Explanation:
Balance equation
Answer:
1,3,2
Explanation:
took test
17 moles of oxygen is equals to how many grams
17 × ( 2 × 16 ) = 17 × 32 = 544 grams
___________________________
Select the correct answer. Which statement is true for a heating curve?
OA. It shows how the pressure of a substance changes when heated.
ов. It shows how the temperature of a substance changes when heated
OC. It shows how the volume of a substance changes when heated.
OD. It shows how the mass of a substance changes when heated.
please help
Answer:
OB
Explanation:
tht is correct make me brainliest
A 25.0mL solution of KOH is neutralized with 30.3 mL of 0.100M HBr. What is the concentration of the original KOH solution?
Answer:
The concentration of the original KOH solution is 0.1212 M.
Explanation:
Dilution is the process to reduce the concentration of solute in solution. This is accomplished by adding more solvent to the same amount of solute. In other words, dilution is the procedure followed to prepare a less concentrated solution from a more concentrated one, and it simply consists of adding solvent to an existing solution.
As only solvent is being added, the consequence is that by not increasing the amount of solute, but if the amount of solvent, the concentration of the solute decreases.
The expression for the dilution calculation is:
Ci* Vi = Cf* Vf
where:
Ci: initial concentration Vi: initial volume Cf: final concentration Vf: final volumeIn this case:
Ci= ? Vi: 25 mL Cf: 0.1 M Vf: 30.3 mLReplacing:
Ci* 25 mL= 0.1 M* 30.3 mL
Solving:
[tex]Ci=\frac{0.1 M*30.3 mL}{25 mL}[/tex]
Ci=0.1212 M
The concentration of the original KOH solution is 0.1212 M.
3. If all of the predators in an ecosystem are killed off,
what happens to organisms that are their food source?
Answer:
its a little bit long but= The most obvious result of the removal of the top predators in an ecosystem is a population explosion in the prey species.More predators kill more prey, which, along with food scarcity, decreases the population. When prey becomes more scarce, the predator population declines until prey is again more abundant.
Use the given Nernst equation and reaction to solve this problem. What is the potential of this cell with the given conditions?
2Li (aq) + F2(g) 2Li+(aq) + 2F- (aq)
E° = +5.92 volts
T = 200°C
[Li+] = 10.0 molar
[F-] = 10.0 molar
Answer:
The 2nd one is the one
Explanation:
and it isn't writen out all the way
4) What is the difference between an atom and an ion?
Answer: Explanation:
Atom means the smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
Iron means a common, inexpensive metal, often black in color, that rusts, is attracted by magnets, and is used in making steel.
Answer: Atoms are neutrally charged; they contain the same number of protons as electrons. By definition, an ion is an electrically charged particle produced by either removing electrons from a neutral atom to give a positive ion or adding electrons to a neutral atom to give a negative ion.
What is the oxidation state of Carbon in CaC2O4?
Answer:
The oxidation state of carbon in CaC204 is 3
At 20°c solubility of sugar is 179.How much gram of sugar is needed to prepare saturated solution with 40gm of water
Answer: Volume is 22,3 ml
Explanation: I assume solubility is expressed to 100 ml water
You can use proportion : 179 g / 100 ml water = 40 gm/ V
Multiplying the proportion gives 179 g · V = 100 ml · 40 g | : 179 g
V = 4000 ml / 179 = 22,3 ml
What is a galvanic cell made of
Answer: A galvanic cell consists of two different metals (electrodes) connected through a conducting solution (an electrolyte) and also connected externally completing a circuit.
How many energy levels does an atom of carbon have?
Answer:
6
Explanation:
What is the number of moles in 10.62 L of H2S gas at STP?
Answer:
0.474 moles
Explanation:
divide 10.62 by 22.4.
When a substance changes from a gas to a liquid, what happens to the energy, order, and spacing of
particles within the substance?
I
Answer:
Explanation:
When gas changes to liquid, it releases the thermal energy that has been absorbed before to become gas which does not alter the temperature at all. A reduction in energy changes the arrangement of particle. There spacing between the particles also increases but not as in a gaseous state and so does the kinetic energy. The particles now are now arranged in irregular pattern.
what is the use of connective tissue
Answer:
Major functions of connective tissue include: 1) binding and supporting, 2) protecting, 3) insulating, 4) storing reserve fuel, and 5) transporting substances within the body. Connective tissues can have various levels of vascularity.
Explanation:
Oxygen has a very low boiling point and is a gas at room temperature. Water has a much higher boiling point and is a liquid at room
temperature. Which of these statements would support these facts?
A)
Oxygen is an element while water is a compound.
B)
Oxygen is diatomic and exist as O2 in nature.
Water has a higher attraction between its molecules than oxygen.
D)
Water is a molecule with 3 atoms and oxygen exists in groups of 2.
Answer is C
(hurry pls)Carl plugs in a lamp that has 0.67 of resistance and 8.1 volts running through it. What is the amount of current running through the lamp? C 543 A C 0.08 A C 12.09 A C743 A
Answer:
C)12.09 Ampere
Explanation:
V= IR
Where I= current of the system
R= resistance= 0.67 ohm
V= potential difference=8.1 volts
Substitute the values
8.1= I× 0.67
I= 8.1/0.67
=12.09 Ampere
La suma de los números de masa de tres isótopos es 126 y la suma de los números de neutrones es 60. Hallar la configuración electrónica de uno de los isótopos, si su carga eléctrica es 1- . b) Determine grupo y periodo para dicho elemento. c) Determine los cuatro números cuánticos para el ultimo electrón. d) Si el elemento que hallaron se une con el elemento flúor que tipo de enlace formará.
A. The electronic configuration for the isotope we want is as follows:
[tex]1s^2 2s^2 2p^6 3s^2 3p^6[/tex].
B. The element belongs to period 3 and group 18.
C.The last electron's four quantum numbers are:
m_s = +1/2 or -1/2 (since the electron can spin up or spin down)
D. With fluorine, the element will develop an ionic connection.
What is an Electronic configuration?The positioning of electrons within an atom, molecule, or other physical structure, such as a crystal, is referred to as electronic configuration. It is typically represented by an array of numbers, letters, or superscripts that denote the number of electrons in each atom or molecule's shell or subshell.
Let the first isotope's mass number be x, the second isotope's mass number be y, and the third isotope's mass number be z. Also, let the first isotope's neutron number be a, the second isotope's neutron number be b, and the third isotope's neutron number be c. Using the information provided, we can construct two equations:
126 = x + y + z (equation 1)
a+b+c=60 (equation 2)
Because all three isotopes contain the same amount of protons, we can infer that their electrical configurations are the same. As a result, all that remains is to determine the electrical structure of one of the isotopes.
We can use the fact that the total of the mass numbers is equal to the amount of protons plus the number of neutrons. Let m be the isotope's mass number and z be the number of protons (the atomic number). Then:
m = z + n, where n is the number of neutrons.
The electrical arrangement of an element can also be used to calculate the atomic number. Assume if the isotope we're seeking for is a periodic table element. The element's electrical configuration can be written as:
[tex]1s^2 2s^2 2p^6 3s^2 3p^6[/tex]
The configuration's last electron is in the (n+1)s or (n+1)p orbital. As a result, we may calculate the atomic number by counting the number of electrons in the arrangement. For example, the atomic number for the aforementioned electrical configuration is 18 (2 + 8 + 8).
Let's look for the electrical configuration of the isotope we're after. Because the element's electrical configuration is not specified, we can presume it is a noble gas. As an example, consider argon (Ar), which has the electrical configuration:
[tex]1s^2 2s^2 2p^6 3s^2 3p^6[/tex]
Because argon belongs to period 3 and group 18 (also known as group 8A), the isotope we seek belongs to period 3 and group 18. This is due to the fact that atoms in the same class have the same amount of valence electrons and chemical characteristics.
As a result, the electrical configuration of the isotope we seek is:
[tex]1s^2 2s^2 2p^6 3s^2 3p^6[/tex]
b) The element belongs to period 3 and group 18.
c) The last electron's four quantum numbers are:
Because the electron is in the 3p orbital, n = 3 l = 1.
Because there are three 3p orbitals, m_l = -1, 0, or 1.
m_s = +1/2 or -1/2 (since the electron can spin up or spin down)
d) With fluorine, the element will develop an ionic connection. Because the element belongs to group 18, it has 8 valence electrons, making it a stable noble gas configuration. It may gain one electron to make a 1- ion or lose eight electrons to form an 8+ ion to obtain this state. Fluorine has seven valence electrons and can gain one electron to produce.
Therefore, the electronic configuration for the isotope we want is as follows:
[tex]1s^2 2s^2 2p^6 3s^2 3p^6[/tex]
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Your question is in Spanish, but the English translation of the question is:
The sum of the mass numbers of three isotopes is 126 and the sum of the neutron numbers is 60. Find the electronic configuration of one of the isotopes if its electric charge is
1- b) Determine group and period for said element.
c) Determine the four quantum numbers for the last electron.
d) If the element they found joins with the fluorine element, what type of bond will it form?
A student wants to determine if a
sample of tap water contains Mg+2.
Which of the following pieces of
information are not needed to do a
titration ?
Answer:
The Density of Magnesium.
Explanation:
can anyone tell me the answer
Answer:
A. A as concentration decreases.
Explanation:
A represents a reactant and B is a product, the concentration of the latter increases at the expense of the concentration of the former. Hence, A is the reactant of the chemical reaction as its concentration decreases.
A student completes a titration by adding 25.0mL of NaOH of unknown concentration to 35.0mL of 0.25M HCl. What is the molar concentration of NaOH? If it takes 15 mL of 0.5M sodium hydroxide solution to neutralize 200 mL of Hydrochloric acid, what is the concentration of HCl? THIS IS TIMED PLEASE HELP! (include work shown)
Answer:
0.35M NaOH and 0.0375M HCl.
Explanation:
NaOH reacts with HCl as follows:
NaOH + HCl → NaCl + H2O
Where 1 mole of NaOH reacts per mole of HCl
To solve the first question we must find the moles of HCl that reacted = Moles NaOH in the unknown. With the moles and the volume we can find its molar concentration:
Moles HCl = Moles NaOH:
0.0350L * (0.25mol / L) = 0.00875 moles NaOH
In 25.0mL = 0.0250L:
0.00875 moles NaOH / 0.0250L =
0.35M NaOH
For the second question, the moles of NaOH = moles HCl. With the 200mL = 0.200L the molarity is:
Moles NaOH = Moles HCl:
0.015L * (0.5mol / L) = 0.0075 moles HCl / 0.200L =
0.0375M HCl
Li + HCl → H2 + Lici
How many moles of air are there in a 125 mL Erlenmeyer flask if the pressure is 755
mm Hg and the temperature is 20.0°C?
To Find :
How many moles of air are there in a 125 mL Erlenmeyer flask if the pressure is 755 mm Hg and the temperature is 20.0°C .
Solution :
Since, air contains different gas in different proportion.
Its average molar mass is considered to be 29 gram/mol .
Now, we know by ideal gas equation :
[tex]PV = nRT\\\\n = \dfrac{PV}{RT}[/tex]
Here, R is ideal gas equation, [tex]R = 62.363\ mm\ Hg\ L \ mol^{-1} \ K^{-1}[/tex]
Putting all given values we get :
[tex]n = \dfrac{755 \times 0.125}{62.363\times (20+273)}\ moles\\\\n = 0.00516 \ moles[/tex]
Hence, this is the required solution.
How many grams are there in 2.5 moles of Ca(OH)2?
Answer: 185 grams
Explanation: First find out how many grams are in one mol: The molar mass es are taken from the periodic table, Ca is 40, O is 16, H is 1. There are 2 O and 2 H for (OH)2: 40+32+2= 74g/mol x 2.5 mol = 185 the moles cancel and you are left with grams
Name of compound 6T ?
Answer:
Explanation:
I serched for it i found name is :sexithiophene
Can someone help on this question.
(10 POINTS!!!!!!!!!!!
What environmental change will take place when harmful substances get into the food and water supply of animals or plants?
A Climate change
B Increased predators
C Lack of food
D Pollution
need asap
Answer:
A climate change
Explanation:
the surrounding area would be effected in all ways imaginable, such as change in air, soil, water, plants, animals. and if you eat those said animals those harmful things can transfur into you