How many oxygen atoms are contained in a sample of aluminum nitrate, Al(NO3)3, with a
mass of 4.285 x 10-21 g? (molar mass of Al(NO3)3 is 213 g mol-l)
a 109
b. 54
c. 9
d. 3
the answer is 9
Explanation:
Explanation: In 1 formula unit of Al(NO3)3 , there are (clearly!) 9 atoms of oxygen, 3 nitrogen atoms, and 1 aluminum atom.
How can mutations occur in cells? Submi Save and Exit Next Mark this and return
by rounding them to the neerest 10
2. How many protons are present in the oxygen atom? *
O A. 24
O B.16
O C.8
O 0.4
Which of these bonds should be classified as ionic?
A.
Na-O
B.
C-S
C.
H-Cl
D.
Be-S
Answer:
Na-O
Be-S
Explanation:
ionic bonds= metal and non metal
Answer:
Na-O
Explanation:
i solved it in study island and i got this answer correct
The water gained 900 J of energy, what was the energy change of the metal?
Answer:
it lost 900J of energy I will assume and that would mean the change in energy is -900J
Explanation:
14. A researcher Is curious to find out what effect classical music has on people's level of relaxation
(as measured by heart rate). She suspects that listening to classical music will make people feel
more calm and relaxed. The researcher lets one group listen to classical music for one hour and
then do a relaxing activity, like reading or drawing for another hour. She lets the other group sit in a
qulet room for two hours (they hear no music). After two hours, she monitors the heart rate of each
participant to measure their level of relaxation.
What is the error in thls experiment design?
A. There are two independent variables: classical music and an additional relaxing activity
B. There are two independent variables: the amount of time and heart rates
C. There are two dependent variables: classical music and an additional relaxing activity
D. There are two dependent variables: the amount of time and heart rates
Answer:
It should be "B"
Explanation:
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Which characteristic is used to classify galaxies?
1. the size of the galaxy
2. the shape of the galaxy
3. the presence of dust and gas between stars
4. the presence of active star formation sites
Answer:
2. the shape of the galaxy
Explanation:
There are four classifications of galaxies and these are: spirals, barred spirals, ellipticals and irregulars. It was Edwin Hubble, an American Astronomer who identified them. They were given such names owing to their shapes. For example, the spiral galaxy looks like it is rotating while the barred spiral galaxy also looks rotating yet it has a bar at the center. Elliptical galaxies have an elliptical shape, similar to that of an elongated circle or an egg. Irregular galaxies don't stick to a particular shape.
Answer:
b
Explanation:
True or False: The moon does not have an
atmosphere, plants, animals or oceans.
Answer:
true
Explanation:
As mentioned above, the moon does not have the same composition as the Earth, and while some of the elements present on the moon are the same, this is likely because of the moon’s formation (the Giant-Impact Theory). In general, this different in composition means that the moon cannot have an atmosphere because it is not geologically active.
Tritium (H-3) is a radioactive isotope of hydrogen with a half-life of 12.3 years. How long would it take for a 40.0g sample to decay down to 1.25g
Answer:
the answer maybe is 61.5 years (please check with others) tq
Explanation:
40/2=20
20/2=10
10/2=5
5/2=2.5
2.5/2=1.25
so one half life is 12.3 years
then 12.3 ×5 =61 .5
(why 5 ? because it decay 5 times to get 1.25 from 20)
cells use oxygen to release energy during blank
Answer:
Cellular respiration
Answer:
cellular respiration
Explanation:
need help with this question plsssss
Answer:
234
Explanation:
Which elements have two valence electrons?
A. Carbon
B. Magnesium
C. Fluorine
D. Sodium
Answer:
Magnesium
Explanation:
Magnesium is in group 2 of the periodic table. The group in which an element is found in tells us the number of valence eletrons it has.
HOPE THIS HELPED
Among the given elements, the element that have two valence electrons is Magnesium. The correct answer is option B.
Valence electrons are the electrons that are present in the outermost shell of an atom that are involved in chemical bonding. The number of valence electrons an atom has is determined by the group number it belongs to on the periodic table.
Magnesium belongs to group 2A on the periodic table, which means it has two valence electrons.
Carbon belongs to group 4A and has four valence electrons, while Fluorine belongs to group 7A and has seven valence electrons. And Sodium belongs to group 1A and has one valence electron.
Therefore, option B. Magnesium is the elements that have two valence electrons.
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These two finches share a common ancestor from South America. What is the most likely way that one ancestral finch species will develop into two distinct species?
A The ancestral species was genetically engineered to become two new species
B Groups of the ancestral species became isolated and adapted to different environments.
C. Two individual birds acquired many spontaneous mutations.
D. The ancestral species mated with other species and the offspring resulted in two new species.
Answer:
The correct answer is - B. Groups of the ancestral species became isolated and adapted to different environments.
Explanation:
Two finches Warbler Finch and Woodpecker Finch are two distinct finches are finches from the Galapagos Islands. Both of these finches have a common ancestor from South America.
The most likely explanation of developing two distinct species from an ancestral finch is by bein isolated and developed or adapted according to the challenges and environmental conditions and ultimately become different species after several generations.
Why is it difficult for hydrogen atoms to stick together
Answer:
So, the energy of two hydrogen atoms is lower when the two atoms are together than when the two atoms are apart; that is why they stay together.
Explanation:
What is one effect of the uneven heating of Earth caused by the Sun? (Answer with a 5 sentence paragraph)
ene
(This is scinece
Answer:
Albedo
Explanation:
Usually when we talk about uneven heating of the Earth's surface we are discussing convection. The uneven heating results in some of the atmosphere to be warmer than other parts and changes in volume and pressure which result in updrafts and can cause thunderstorms and other violent weather. The cause of this is the reflectiveness of the surface of the Earth at that point (the albedo) and the angle that the sun's rays strike it at. A field covered with snow and ice is going to be much more reflective than a black top asphalt parking lot. As such the parking lot absorbs much more shortwave radiation from the sun and gets much warmer.
The uneven heating of Earth caused by the Sun craetes the difference in the atmosphere pressure and the volume of gasses present in atmosphere.
What is uneven heating of Earth?The uneven heating in the atmosphere disturbs the climatic conditions as there are some areas which are cold and some are hot then before and also changes the volume and pressure.
The change in the volume and the pressure results in the flow of the upward flow of the current air which is the main cause of thunder storm and some other climatic disaster can also happen.
Therefore, uneven heating of Earth caused by the Sun craetes the difference in the atmosphere pressure and the volume of gasses present in atmosphere.
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Of sulfuric acid, carbonic acid, nitric acid, and hydrochloric acid, which one is considered a weak acid
Answer:
nitric acid is considered as a weak acid
The strong acids are hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, perchloric acid, and chloric acid. The only weak acid formed by the reaction between hydrogen and a halogen is hydrofluoric acid
I need help really bad with this!!!
For the following:
Highlight each subscript in RED.
Highlight each coefficient in BLUE.
H2O 5Cl2 2Mg 3H2O2
For the following
List the chemical symbols of each element.
Give the number of atoms of each element.
HCl CO2 Na2SO4
Balance the following chemical equations.
1. Cu2O + C → Cu + CO2
2. H2O2 → H2O + O2
Al + Fe3N2 → AlN + Fe
4. Ag2S → Ag + S8
5. ZnS + AlP → Zn3P2 + Al2S3
6. Fe(OH)3 → Fe2O3 + H2O
Given the two chemical equations, highlight in RED the one that is balanced.
7. a. 2Na + Cl2 → 2NaCl
b. 2Na + 2Cl2 → 2NaCl
8. a. C3H8 + 5O2 → 3CO2 + 4H2O b. 2C3H8 + 5O2 → 3CO2 + 8H2O
9. a. 2NH3 + 5O2 → 2NO + 3H2O b. 4NH3 + 5O2 → 4NO + 6H2O
10. a. Y(NO3)2 + GaPO4 → YPO4 + Ga(NO3)2
b. 2Y(NO3)2 + 2GaPO4 → 2YPO4 + Ga(NO3)2
Answer:
Did u get the answers
Explanation:
what do water, air and rocks have in common
Summarize the history of radioactivity by choosing the scientist(s) involved with each discovery.
conducted experiments with uranium-containing minerals and pure uranium.
came up with the term “radioactivity.”
showed that uranium in a mineral gave off radiation even without being exposed to the Sun.
discovered radium and polonium.
conducted experiments with fluorescent minerals and photographic plates.
Answer:
Marie and Pierre CurieMarie and Pierre CurieAntoine Henri BecquerelMarie and Pierre CurieAntoine Henri BecquerelExplanation: Correct on Edg 2020/2021.
Which of the following could be the speed of an object at rest?
0 m/s
-4 m/s
20 m/s
1 m/s
Answer:
0 m/s
Explanation:
An object at rest stays at rest unless acted upon therefore it can only be 0.
Consider the reaction below.
2NH318) N26 + 3H20)
What is the most likely effect to the forward reaction if there is an increase in pressure on this reaction?
O The reactant surface area increases.
O The reaction rate decreases.
O The reaction is not affected at all.
O The reaction stops completely.
Answer:
B. The reaction rate decreases
Explanation:
I just took the pre test and got a 100
How is chemical bonding useful to our lives?
Answer:
Three types of chemical bonds are important in human physiology, because they hold together substances that are used by the body for critical aspects of homeostasis, signaling, and energy production, to name just a few important processes. These are ionic bonds, covalent bonds, and hydrogen bonds.
Explanation:
1. What did Henri Becquerel discover about
radiation emitted from uranium salts?
Explanation:
When Henri Becquerel investigated the newly discovered X-rays in 1896, it led to studies of how uranium salts are affected by light. By accident, he discovered that uranium salts spontaneously emit a penetrating radiation that can be registered on a photographic plate.
the empirical formula for a compound used as a green paint pigment is C2H3As3Cu2O8. The molar mass of its molecular formula was found to be 1013 grams. What is the molecular formula?
Answer:
Molecular formula = C₄H₆As₆Cu₄O₁₆
Explanation:
Given data:
Empirical formula = C₂H₃As₃Cu₂O₈
Molar mass of compound = 1013 g/mol
Molecular formula = ?
Solution:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass of C₂H₃As₃Cu₂O₈ is 506.897 g/mol
by putting values.
n = 1013 / 506.897
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 (C₂H₃As₃Cu₂O₈)
Molecular formula = C₄H₆As₆Cu₄O₁₆
What is the temperature (in °C) of a room where the gas has a volume of 0.635 L at 1 atm?
When does the number of electrons be greater than the number of protons?And give examples.
Answer:
This accepting atom will then become an anion. The anion has more electrons than protons. This means that some of the electrons will not be canceled out, giving the atom an overall negative charge.
If an object has more protons than electrons, then the net charge on the object is positive. If there are more electrons than protons, then the net charge on the object is negative. If there are equal numbers of protons and electrons, then the object is electrically neutral.
Explanation:
Why do cat always land on their feet???
Answer:Cats’ ability to land on their feet can be chalked up to the “righting reflex” that they possess:)
Explanation:
Someone help please!!!
HELP PLEASE <3 !!!!!!
Why Do Some Things Stop While Others Keep Going?
Answer:because they run out of energy when it is transferred and to other objects, or their kinetic energy
Explanation: