Which information best supports the idea that the universe began with rapid expansion?
O Measurements of cosmic microwave background radiation
O Measurements of rates of decay
O Calculation of the temperature and brightness of stars
Calculations of the distance from the sun to each planet
The element magnesium is a
O Group 12, Transition Metal
O Period 3, Alkaline Earth Metal
Period 4. Alkali Metal
O Period 4, Halogen
In the following reaction, how many grams of H2O are produced if 2.00 g of N2H4 react? N2H4 + 3 O2 ---> 2NO2 + 2H2O
Answer:
2
Explanation:
From this equation, 2 grams are produced.
The mass of H₂O produced from the reaction is 2.25 g
We'll begin by calculating the mass of N₂H₄ that reacted and the mass of H₂O produced from the balanced equation.
N₂H₄ + 3O₂ —> 2NO₂ + 2H₂O
Molar mass of N₂H₄ = (2×14) +(4×1) = 32 g/mol
Mass of N₂H₄ from the balanced equation = 1 × 32 = 32 g
Molar mass of H₂O = (2×1) + 16 = 18 g/mol
Mass of H₂O from the balanced equation = 2 × 18 = 36 g
SUMMARY
From the balanced equation above,
32 g of N₂H₄ reacted to produce 36 g of H₂O.
Finally, we shall determine the mass of H₂O produced by the reaction of 2 g of N₂H₄From the balanced equation above,
, 32 g of N₂H₄ reacted to produce 36 g of H₂O.
Therefore,
2 g of N₂H₄ will react to produce = (2 × 36) / 32 = 2.25 g of H₂O
Thus, the mass of H₂O produced from the reaction is 2.25 g
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Which method is used to assign numerical ages to events or materials?
Answer:
radiometric dating methods
Explanation:
To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.
Answer:
Absolute Dating
Explanation:
took the test
How does a balanced chemical equation demonstrate conservation of mass?
Answer:
A balanced chemical equation will demonstrate the law of conservation of mass because the amount of elements on one side (reactants) will equal the amount of elements on the other side (products).
Explanation:
CH₄ + 4Cl₂ -> CCl₄ + 4HCl
Reactants:
1 C
4 H
8 Cl
Products:
1 C
4 H
8 Cl
How can subsidence lead to the
formation of sedimentary rock?
Answer:
the process when crusts sink into the seafloor and go further into the mantle. When sediments are compacted and cemented together with the limestone and other rock particles at the ocean floor, a sedimentary rock is formed. ...
Explanation:
Lithium has two isotopes, lithium-6 weighing 6.015 amu (7.5% abundance), and lithium-7
weighing 7.016 amu (92.5% abundance). What is the atomic mass of lithium?
with calculations
Answer:
The answer is 6.941 but I dont really have the explanation
Explanation:
The atomic mass of lithium will be 6.9458 amu.
What is Atomic Mass ?
The mass of an atom of a chemical element expressed in atomic mass units.
It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
Calculation :
Consider 10000 atoms of Li ;
742 of them would have mass 6.02.9258 of them would have mass 7.02.
Hence,
The total mass of these 10000 Li atoms would be ;
(742 × 6.02) + (9258 × 7.02) = 69458
∴ 1 Li atom on average would have mass = 69458 / 10000 = 6.9458 amu
Therefore, The atomic mass of lithium will be 6.9458 amu.
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Why are supergiant so bright?
Because supergiants are so massive, the core temperature gets much hotter than in giants, so supergiants can fuse elements heavier than hydrogen and helium. But to support their tremendous mass, supergiants burn up their fuel much more quickly.
Answer:
because the core tempature gets much hotter.
Explanation:
so supergiants can fuse elements heavier than hydrogen and helium. But to support their tremendous mass, supergiants burn up their fuel much more quickly.
Which of the following statements are incorrect?
A. A sodium atom has a smaller radius than a potassium atom.
B. A neon atom has a smaller radius than an oxygen atom.
C. A fluorine atom has a smaller first ionization energy than an oxygen atom.
D. All are statements are incorrect
b is the answer because oxyen atom has a smaller radius
Answer: B
Explanation:
7th grade help me plzzzzzzzz
Answer:
1. Metals
2. Solid, gas, liquid
Explanation:
For #1:
The majority of elements in the periodic table are classified as metals. The transition metals lie in the center of the table, spanning groups three through 12. These elements are solid at room temperature, except mercury, and have the metallic color and malleability expected of metals.
Hope this helps :)
Meh peepss halp will mark brainliest!!!! u-u
Answer:
The three parts of the cell theory are as follows: (1) All living things are made up of cells, (2) Cells are the smallest units (or most basic building blocks) of life, and (3) All cells come from preexisting cells through the process of cell division. ... Today, the cell theory is considered the foundation of biology.
Explanation:
hope this help.. brainliest???
Answer:
i wanna give brailiest to the person at the top!
Explanation:
221 A grocery shop has different types of fruit: one box contains 10 mangos, another
contains 7 avocados and the third box contains 5 lemons.
The same shop has 20% organic food. 50% inorganic food, and 30% of the things they sell
are juices.
3 marks)
A) Represent the types of fruit in bar graph.
B) Represent the sales in pie graph.
Answer:
A) Please see the required bar graph attached
B) Please see the required pie graph attached
Explanation:
The given data are;
The number of each fruit in each box are;
First box contains 10 mangoes
Second box contains 7 avocados
Third box contains 5 lemons
The percentage of the things they sell are;
Organic food = 20%
Inorganic food = 50%
Juices = 30%
A) The bar graph is plotted with Microsoft Excel
The height of each column is equivalent to the number of fruit in the box
Each column represents a box of fruit
B) The pie graph (chart) is generated with Microsoft Excel
The steps to draw the pie chare are;
1) Draw a circle
2) Partition the circle into segments proportional to each percentage from the center of the circle as follows;
The sum of angles at the center of the circle = 360°
The angle of the segment that will represent the 20% organic food in the pie chart = 20/100 × 360° = 72°
Therefore, the segment representing organic food will have an angle of 72° at the center of the circle
Similarly, the segment representing inorganic food will have an angle of 50/100 × 360° = 180° at the center of the circle
The segment representing juices will have an angle of 30/100 × 360° = 108° at the center of the circle.
How many number of oxygen molecules are required to produce 0.22 g of CO2 according to the reaction?
c+o2=co2
The first noble gas with a Lewis Structure with 8 dots is
A. Ar
B. Kr
C. He
D. ne
Answer:
C) He
Explanation:
Helium is one of the noble gases and contains a full valence shell. Unlike the other noble gases in Group 8, Helium only contains two valence electrons.
How can electronegativity be used to explain the reaction we see in terms of the numbers and types of bonded being formed in lithium?
Explanation:
Lithium is an electropositive element that readily loses electrons.
Oxygen is electronegative and it will readily accept electrons.
Due to this significant electronegativity differences between the two species they form electrovalent or ionic bonds between them.
2atoms of Li lose two electrons:
Li → Li²⁺ + e⁻
Lithium isoelectronic with helium
For oxygen;
O + 2e⁻ → O²⁻
Oxygen is isoelectronic with Neon
Two ions of the lithium combines with the oxygen to form the bond;
4Li + O₂ → 2Li₂O
The electrostatic attraction between the two ions forms the ionic bond
Colleen waters the plants in her greenhouse once every day. She wants to find out if the plants will grow more leaves if they are watered more often. She counts the number of leaves on each plant before she starts. She then continues to water half of each type of plant once daily, but she waters the other half of each type twice a day. What is the dependent variable in Colleen's experiment?
Examine the layers of rock. How does layering provide evidence for determining geologic age?
Answer:
the deeper you go down in to the rock the older the fossils get.
Explanation:
layering can provide evidence because the deeper you go down in to the rock the older the fossils get. So when the scientists go in to the rock they can say what animals lived in that time and what animal was the oldest.
A solid is composed entirely of xenon atoms. What type of solid is it?
a) ionic
b) metallic
c) covalent network
d) atomic
e) molecular
f) amorphous
Answer:
ionic
Explanation:
xenom atoms are too large to move in the crystals without first associating with two oxygen ion vacancies and one uranium ion vacancy
what is S oxidation number
the answer to you question is -2
Consider the equation:
Ca+O2→CaO
What needs to be done in order to balance the equation?
Place a 2 in front of the Ca and the CaO.
Place a 2 in front of the O2 and the CaO.
Place a 2 in front of the CaO only.
Place a 2 only in front of the Ca.
Which of the following atoms has the smallest atomic radius?
A. F
B. Li
C. C
D. Be
Answer:
A) F
It has the smallest atomic radius.
Perform the following
mathematical operation, and
report the answer to the correct
number of significant figures.
7.68 x 4.564 = [?]
Answer:
35.05152
Explanation:
Answer:
35.1
Explanation:
I put that answer in and it was correct.
What is an ionic compound? Describe and give an example.
Answer:
Ionic compounds are compounds made up of ions. These ions are atoms that gain or lose electrons, giving them a net positive or negative charge. Metals tend to lose electrons, so they become cations and have a net positive charge. Ions of opposite charge are held together by very strong ionic bonds within the compound.
Explanation:
My explanation is above with the answer
How do slab pull forces affect plate motion? Choose the correct answer.
Uplifted mantle causes plates to move apart.
Convection currents drive the plate downward to move it.
Earthquakes break the crust into smaller plates to make motion easier.
The weight of the subducted plate produces a force to continue moving the plate.
Answer:
The weight of the subducted plate produces a force to continue moving the plate.
Explanation:
How much eat is absorbed when 50.0g of water changes from 25.0 Celsius to 37.0 Celsius?
Which is the best description of a molecule?
Answer:
A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms.
Answer:
C
Explanation:
Emma draws a sketch of what happens to light as it moves through air and then into a tank of water. describe what happens to the speed of light as it enter the water.
Answer if you know, if you don't move on please! If you don't know comment not answer. Thank you!!
Answer:
The speed of light becomes slower in denser medium which is water in this case.
Explanation:
We know the lens law of Refraction which states
[tex]\frac{Sin(i)}{Sin(r)} =[/tex] Refractive index of second medium /Refractive index of the first medium
= Velocity of light in medium 1 (V1)/ velocity of light in medium 2 (V2)
When light rays fall from air medium into water which is a denser medium bending of light or change in the direction of light occurs which is knows as Refraction.
When refraction occurs speed of the light rays are also varied as we can see it from the Lenz's Law. suppose two light rays parallel to each other falling on the air-water interface at an angle , the first ray will reach the interface and bend about the normal and then the second ray. We also observe when light enters denser medium the speed of light becomes slower, also the bending of light when going from rarer to denser it bends towards normal of the surface and when it move from denser to rarer medium it moves away from the normal to the surface.
The compound whose molecules have the highest average kinetic energy is?
Answer:
C)
Explanation:
The warmer the molecules, the higher the average kinetic energy.
"As stated in the kinetic-molecular theory, the temperature of a substance is related to the average kinetic energy of the particles of that substance. When a substance is heated, some of the absorbed energy is stored within the particles, while some of the energy increases the motion of the particles. This is registered as an increase in the temperature of the substance." -lumen learning
(I know for sure but what think... hope this helped)
help please I will give brainliest to the best answer
Answer:
the correct answer is D
Refer to the above image. Which of these is NOT found in the nucleus of an atom?
A
Neutrons
B
Protons
С
Atomic mass
D
Electrons
Answer:
Atomic mass
Explanation:
I got it right on my test