Answer:The limestone began to form millions of years ago, when the land was under the ocean. The rock developed from shells of tiny organisms that float in the ocean. ... However, in the case of reefs, the limestone is produced directly as coral organisms build their skeletons one on top of another.
An atom of an element has 2 electrons in the 1st energy level and 5 on the 2nd energy level what element is it ?
the element is nitrogen
5+2=7
Why are molecular covalent compounds insoluble in water?
Answer:
Hope this will help.......
Explanation Covalent bonds are insoluble in water (H2O) , but covalent compounds are. This is because some organic compounds (covalent) contain the polar −OH group which can bond to a hydrogen ion to form water.
I need help with the bottom part of the paper
Answer:
ur really pretty :)
Explanation:
Here is a model of the sun earth system at a certain point in earths orbit around the sun based on the model which statement best explains my point is is experiencing summer
Answer:
the earth is tilted towards the sun
Explanation:
In the context, there is a sun and earth system and at a certain point when the earth is moving in its orbit around he sun, some point on the earth experiences the summers season. This is because at this point of the earths revolution, the point on the earth is facing the sun and is also tilted towards the sun. So at this point the sun rays fall directly at the surface. While the place which is tilted away from the sun, experiences winter season.
Answer:
Earth's northern hemisphere is tilted toward the Sun.
How is a "decay event' recorded
Help pleasee I need help to write the formulas i’m so lost
Answer:
NH4
Explanation:
¿Por qué un trozo de sal común es frágil y se puede romper fácilmente cuando se le somete a una fuerza y no ocurre lo mismo con un trozo de metal que se deforma antes de romperse?
Answer:
Explanation:
La sal común es un compuesto iónico, es decir que sus átomos (Na y Cl) están unidos entre sí por fuerzas electrostáticas, y el metal está unido entre sí por uniones metálicas. La naturaleza de estas uniones es diferente y en base a las fuerzas de atracción que hay entre los átomos en compuestos con este tipo de uniones, la propiedades físicas generales serán diferentes.
En el caso de los metales, los átomos metálicos están colocados unos sobre otros de forma ordenada, pero no fijamente retenida, y los electrones de valencia están delocalizados a través de todo el cristal metálico. Por esta razón, cuando se le aplica una fuerza a un metal, estos átomos pueden deslizarse unos sobre otros. Ésta es la propiedad que le da a los metales su maleabilidad.
En el caso de los compuestos iónicos, los aniones y cationes que lo componen están ordenados en el cristal de una forma más rígida y por eso cuando se les aplica una fuerza éstos compuestos se rompen mucho más fácil, ya que no pueden deformarse.
please show the work :(What is the estimated force applied to the box if the acceleration is .40 m/s2?
force (N) acceleration (m/s2)
10 .20
? .40
Answer:
20N
Explanation:
Given parameters:
Force(N) Acceleration(m/s²)
10 0.2
? 0.4
Unknown:
The force applied when the acceleration is 0.4m/s²
Solution:
From newton's second law of motion;
Force = mass x acceleration
Since we are using the same box, let us find the mass of the box;
Force = mass x acceleration
10 = mass x 0.2
mass = [tex]\frac{10}{0.2}[/tex] = 50kg
Now,
The force in the second instance will be;
Force = 50 x 0.4 = 20N
List the following particles in size order, from biggest to smallest?
A Molecules, electrons, atoms incorrect answer
B Atoms, molecules, electrons incorrect answer
C Electrons, atoms, molecules incorrect answer
D Molecules, atoms, electrons
Answer:
D. Molecules, atoms, electrons.
Explanation:
I did a quiz on this and got it right
Answer:
D. Molecules, atoms, electrons.
Explanation:
i did the test trust i got it right
What are the advantages of using resources such as geothermal energy, solar energy, and hydropower?
They produce large amounts of energy from burning fuels.
They can generate power by burning wastes.
They come from energy sources that never run out.
They increase the amount of greenhouse gasses.
A 2.9 kg model rocket accelerates at 15.3 m/s2 with a force of 44 N. Before launch, the model rocket was not moving. After the solid rocket engine ignited, hot gases were pushed out from the rocket engine nozzle and propelled the rocket toward the sky.
Which of Newton’s laws apply in this example? Check all that apply.
Answer:
newton's firts law
Explanation:
because it states that everybody continue its state in rest unless an external force is appy to change its state from rest to motion.
Answer:
A, B, C
Explanation:
I need someones help
Answer:
y or z one of those two i think its z but im so sorry if im wrong if not z then try y also I learned this last year.
What Most Often Causes The Availability Of Water To Change?
A. type of plants
B. type of soil
C. local geography
Answer:the answer is C
Explanation:
Which gas is made from more than one element?
What is the mass of 1.794 mol Ba(NO3)2?
Explanation:
Molar mass of Ba(NO3)2 = 261.3368 g/mol
The chemical equation represents a reaction between ammonia and oxygen to form nitrogen monoxide and water. 4 N H 3 ( g ) + 5 O 2 ( g ) → 4 NO ( g ) + 6 H 2 O ( g ) What is the limiting reagent when a 4.50 g sample of ammonia is mixed with 15.80 g of oxygen?
The limiting reagent : NH₃
Further explanationA method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients, and small or exhausted reactants become a limiting reactant
Reaction
4NH₃(g)+5O₂(g)⇒4NO(g)+6H₂O(g)
mol NH₃ :
[tex]\tt \dfrac{4.5}{17}=0.265[/tex]
mol O₂ :
[tex]\tt \dfrac{15.8}{32}=0.494[/tex]
mol ratio
NH₃ :
[tex]\tt \dfrac{0.265}{4}=0.06625[/tex]
O₂ :
[tex]\tt \dfrac{0.494}{5}=0.0988[/tex]
Limiting reactants : NH₃ (smaller ratio)
The limiting reagent when a 4.50 g sample of ammonia is mixed with 15.80 g of oxygen is NH₃
Calculation of limiting reagent:The limiting reactant refers to the reactant that gets consumed first in a chemical reaction and thus it limits how much product can be created or developed. A method that can be used to determine limiting reactants that to divide the number of moles by their respective coefficients.
So,
For mol NH₃ :
[tex]= 4.5\div 17[/tex]
= 0.494
For mol O₂ :
[tex]= 15.8 \div 32[/tex]
= 0.494
For mol ratio
NH₃ :
[tex]= 0.265 \div 4[/tex]
= 0.06625
O₂ :
[tex]= 0.494 \div 5[/tex]
= 0.0988
Based on the above calculations we can say that it is NH₃
learn more about the oxygen here: https://brainly.com/question/19803828
How do you separate a mixture?
Answer:
We can seperate a mixture by various methods
Explanation:
Distillation, Evaporation, filtration and chromatography
Select all that apply. Choose the chemical formulas that are matched with their
correct name.
MgF2, magnesium (II) fluoride
BeO, beryllium oxide
NaCl, sodium chloride
AlF3, aluminum trifluoride
CaCl2, calcium chloride
Answer:
i think just these
NaCl
CaCl2
Which of the following is TRUE about when two atoms form a bond? a. Repulsion is greater than attraction b. Neither atoms will have a full valence shell c. Potential energy is at a minimum
Answer:
b: Neither atoms will have a full valence shell
Explanation:
I think sooo
What is the best explanation of an organelle?
An organelle is a structure within the cytoplasm of a eukaryotic cell that is enclosed within a membrane and performs a specific job. Although ribosomes are not enclosed within a membrane, they are still commonly referred to as organelles in eukaryotic cells.
Answer: A organelle is a structure within the cytoplasm of a eukaryotic cell that is enclosed within a membrane and performs a specific job and although ribosomes are not enclosed within a membrane, they are still commonly referred to as organelles in eukaryotic cells.
The movement of air caused by differences in air pressure is __________________.
Answer:
wind
Explanation:
it would be naturally caused by the pressure
Answer:
temperature or pressure differences
Explanation:
which of the following lists show the elements in order, from those having the least protons to those having the most protons in the atoms?
A. K, Mg, N, O
B. C, Al, P, Cl
C. Li, Be, H, He
D. Na, Ne, He, H
The elements that have least protons to those having the most protons in the atoms are:
B. C, Al, P, Cl
Protons in an atom:There is an equal number of protons and electrons in an atom. So when moving across a period in a periodic table the number of electrons increases which also shows the increases in a number of protons. So as the atomic number increases, the number of protons and electrons also increases.
Thus, the order of elements having least to greatest protons are:
C, Al, P, Cl
C has 6 atomic number, Aluminium has 13 atomic number , Phosphorus has 14 atomic number and atomic number of chlorine is 17.
Thus, option B is correct.
Find more information about Atomic number here:
brainly.com/question/1805828
What mass of NO2 can be produced when 678 mL of oxygen at STP and 256 grams of NH3 are mixed together?
Answer:
WHT55
Explanation:
i experianced this before
how to write the ionic formula for the K1+, MnO41- pair of ions
Answer:
Ionic formula: KMnO4
Explanation:
Pottasium permanganate (KMnO4) is an ionic compound that contains a combination of pottasium cations (K+) and permanganate anion (MnO4-). The pair of ions that make up the ionic compound cancel out each other to make it neutral.
K+ (aq) + MnO4- (aq) → KMnO4 (aq)
MnO4- contains 1 atom of manganese with a (+7) charge and four atoms of oxygen with a (-2) charge each. This forms a +7 for Mn and -8 for O4, hence, a net total of -1.
A piece of silver is heated and added to a styrofoam cup calorimeter containing 26.0 mL (the density of water is 1 g/mL) of water at 19 oC. The water reaches a maximum temperature of 44 oC after the metal was added. If the specific heat of the silver is 0.240 J/g oC and it started at 93.8 oC
Answer:
m(Ag) = 227.5g
Explanation:
...what is the mass of the piece of silver?
The heat given for the piece of silver is the same heat that is absorbed for the water, that is:
m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)
m is mass of water in solution: 26.0mL = 26g of water
And m(Ag) is the mass of Ag, our incognite.
C is specific heat (0.240J/g°C for Ag), and 4.184J/g°C for water
ΔT is change in temperature (93.8°C - 44°C = 49.8°C) for Ag ad (44°C - 19°C = 25°C)
Replacing:
m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)
m(Ag)×0.240J/g°C×49.8°C = 26g×4.184J/g°C×25°C
m(Ag)* 11.952J/g = 2719.6J
m(Ag) = 227.5g
melting is considered a(n) ___ change because energy is gained by the substance as it changes state
A. Physical.
B. Chemical.
C. Volume.
D. Dynamic.
Which of the following best defines a basic solution?
Which of the following set of atoms has the largest electronegativity difference?
a. H and P
b. N and C
c. Li and O
d. Cl and Ca
Answer:
C
Explanation:
Li has an electronegativity of 0.98, O has an electronegativity of 3.44. 3.44-0.98= 2.46 electronegativity differnece :)
help me out plz!!!!
WILL MARK YOU BRAINLEIST What do sound waves need to have to travel from one place to another?
What do sound waves need to have to travel from one place to another?
Question 5 options:
steel
water
air
a medium
Answer:
a medium!!!!
Explanation:
ITS CORRECT!!!! I GOT IT RIGHT ON MY TESTTTTT! I PROMISEEE