Answer:true
Explanation:
definition of atomic number
Predict the empirical formula of the ionic compound that forms from aluminum and oxygen.
A. AIO.
B. Al2O.
C. Al2O3.
D. Al3O2.
E. AlO2.
Answer:
A. AlO
Explanation:
The empirical formula of a compound is the simplest possible formula giving the ratio of atoms in a molecule of the compound.
We know that Aluminium forms [tex]Al^{3+}[/tex] and oxygen forms [tex]O^{2+}[/tex].
As such the formation of the ionic compound between a metal and non-metal results into [tex]Al_2O_3[/tex].
The empirical formula is as follows:
Element Aluminium Oxygen
% composition
by mass 26.98 16.0
mole ratio 26.98/26 16/16
= 1.04 = 1
divided by the
smallest number 1.04/1 1/1
1.04 1
The empirical formula is AlO
What is the volume of as sample that has a mass of 40.0 g and a density of 4.30 g/mL?
Explanation:
density = mass/volume so volume = mass/density = 40/4.30
Briefly summarize how heavy elements are created
Answer:
Heavy elements are created by fusing two elements together in a lab. They look for “events” that comprise a series of alpha decays that result in spontaneous fission.
Explanation:
Atoms of different element can not have same atomic number because only same type of atoms combine to form element. Atoms belonging to different element can have different atomic number. Therefore, in below given ways we can summarize how heavy elements are created.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
Elements heavier than iron cannot be created by fusion because the reaction requires energy to occur. We do, however, perceive elements other than iron all around us. This is accomplished by supernova explosions, which result in neutron capture processes and the production of heavy materials.
Therefore, in above ways we can summarize how heavy elements are created.
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Based on what you observed, what ideas do you
have about the missing piece? What can you
visualize about the missing piece?
Which acid
is synthetic and not found in
nature?
Answer:
because acids come from various chemical substances
Which of the following is not a theory supporting global warming?
a.
It is predicted that the average temperature will rise 1.4° C or more over the next 100 years.
b.
Human activity has increased greenhouse gases.
c.
Over the last 100 years the earth has warmed by 0.74° C
d.
Carbon dioxide is an insignificant greenhouse gas.
A theory that is not supporting global warming is Carbon dioxide is an insignificant greenhouse gas. D is correct.
What is global warming?Global warming is the long-term heating of Earth’s surface observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere. This term is not interchangeable with the term "climate change."
Our world is heating up. Because of global warming, temperatures are increasing and extreme weather is becoming more common. If we don't take preventative action now, future generations will be faced with warmer temperatures, as well as higher sea levels, extreme weather events, crop failures, extinctions, and other devastating effects.
Greenhouse effect is the reason for global warming and it happens because of absorption of gases like CO₂ and CH₄ in our environment.
Therefore, A theory that is not supporting global warming is Carbon dioxide is an insignificant greenhouse gas. D is correct.
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whats an organic chemist
A student determines the volume of a rock is 12.3mL, but the rock is
actually 12.5mL. What is the percent error? Select the BEST answer.
Answer:
1.6%
Explanation:
12.5 ml - 100%
12.3 ml - x %
x = (12.3*100)/12.5
x = 98.4%
Error = 100 - 98.4 = 1.6%
Which of the following is an element? aluminum bronze table salt brass
Answer:
Aluminum is an element
Explanation:
Aluminum is the most abundant metal in the earths crust with an atomic number of 13.
Two objects are moving in a straight line. One object has a faster speed than the other. They both have constant speeds (speed is not changing). Is either object accelerating?
Answer:
No
Explanation:
Acceleration refers to the increase in speed over time. Since both of the objects are moving at a constant speed (so the speed is not changing) neither are accelerating, because acceleration requires a positive change in speed.
They may be moving at different speeds, one faster than the other, but neither are changing their own speed so neither are accelerating.
Hope this helped!
Which is an example of what should be done in case of a laboratory accident? Wear appropriate lab attire. Read directions completely. Do not try to clean up a spill. Remain in the area.
Answer: C. Do not try to clean up a spill.
Explanation:
Which subatomic particles were discovered, disproving the part of Dalton's atomic theory that said an atom is "indivisible?" Question 3 options: A) neutrons B) ions C) protons D) electrons E) isotopes
Answer: D) Electrons
Explanation:
Daltons atomic theory was electrons
Where light is hitting an object
The phrase "where light is hitting an object" refers to the specific points or areas on the surface of an object that are directly exposed to light.
These are the regions where photons from a light source directly interact with the object's surface.
When light hits an object, it can be absorbed, reflected, or transmitted depending on the object's properties. The areas where light is hitting will typically appear brighter or illuminated, while the areas in shadow or not directly exposed to light will appear darker.
The distribution of light hitting an object plays a crucial role in determining its visibility, color, and overall appearance.
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Caves are formed by: i)solution ii)oxidation iii)carbonation iv)hydration
Answer:
i think its oxidation
Explanation:
How many electrons are found in a C and O2-, respectively?
Answer:
For example: O2- indicates an ion of oxygen having two extra electrons. I.e., since an oxygen atom normally has 8 protons and 8 electrons, this ion has 10 electrons (-10 charge) and 8 protons (+8 charge) giving it a charge of -2 (-10 + 8 = -2).
Carbon has a total of six electrons and there are a total of ten electrons in the oxygen ion.
What we can easily find in common with carbon and oxygen atom is the fact that the both of them have two shells. We can also refer to these shells as energy levels.
In both atoms, the first shell contains only two electrons. For carbon, the second shell contains four electrons while the second shell of oxygen ion contains eight electrons.
Hence, Oxygen ion has two electrons in the first shell and eight electrons in the second shell(total of ten electrons) while carbon has two electrons in the first shell and four electrons in the second shell (a total of six electrons).
The electronic configuration of carbon is: 1s2, 2s2, 2p2
The electronic configuration of oxygen ion is: 1s2, 2s2, 2p6
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2. What is the ratio of protons to electrons in all normal atoms?
Given :
Normal atom.
To Find :
The ratio of protons to electrons in all normal atoms.
Solution :
Here normal atom means neutral atoms i.e atoms whose charge is zero.
Atom charge is zero when number of proton are equal to number of electrons.
[tex]N_p=N_e[/tex]
So, [tex]\dfrac{N_p}{N_e}=1[/tex]
Therefore, the ratio of protons to electrons in all normal atoms is 1.
Hence, this is the required solution.
Andrew walks through his garden and observes that the shapes of dewdrops are not always the same. Suppose he wants to investigate using the scientific method. Which questions are testable questions that he can ask to look into the reasons for the different shapes?
Answer: A, C, E
Explanation: PLATO. all testable questions.
You are calling the telephone company to discuss your bill. Your expected wait time on hold is
20,000,000,000,000,000,000 fs.
(a) Convert this time to seconds and decide if you would be willing to wait this long.
(b) What is this length of time in minutes?
(c) What is this length of time in years?
Answer:
(a) 20,000 seconds
(b) 333.33 repeating minutes
(c) 0.0006341958 years
Give 5 examples of branches of science, then give an example of situations that apply the use of it in daily activities. Example: PHYSICS - Turning the light on and off.
Answer:
See explanation
Explanation:
Biology- digestion of food materials
Chemistry- dissolving salt in water
Astronomy - observing day and night
Physics - watching a television
Geography - observing weather changes during the day
A chemist is testing the quality of a wine produced by a vineyard. Which branch of chemistry might the chemist use? physical chemistry analytical chemistry inorganic chemistry organic chemistry
Answer:
organic chemistry
Explanation:
There are many branches of chemistry. Some of them are physical chemistry, analytical chemistry, inorganic chemistry and organic chemistry.
A chemist is testing the quality of a wine produced by a vineyard. It means he will test the structure, properties, and preparation of wine. All these tests comes under organic chemistry.
Hence, the correct option is (d) "organic chemistry"
Answer:
analytical chemistry
Explanation:
I took the test
How are the molecules in the cell membrane arranged? as a lipid bilayer as a protein bilayer as a carbohydrate bilayer as a DNA bilayer
Answer:
as a lipid bilayer
Explanation:
just took the test
Answer:
A. as a lipid bilayer
Which phrase best describes igneous rocks?
form when lava and magma cool
accumulate sediments following erosion
require heat and pressure to be formed
consist of many sediment layers
Answer:form when magma and lava cool :/
Explanation:hope this helps, and I’m this because ingenious rocks are made/ formed from magma and lava.
The phrase which best describes igneous rocks is option A, .i.e., it forms when lava and magma cool.
What is igneous rock?Igneous rocks are formed by the melting of earth's crust into magma, . The two types of this rocks are, Extrusive and intrusive igneous rocks . The slow cooling of magma beneath the surface results in intrusive igneous rock.
Magma in the crystal is in molten liquid state which heat by convection and flows out. This creates slight movement in plates and the hot mantle the cools down to form igneous crystals.
Extrusive igneous rock is created when lava above the surface cools quickly. The magma hardens more quickly after being brought to the surface via cracks or volcanic explosions. As a result, these rocks are crystalline, smooth, and fine-grained.
Thus regarding the formation of igneous rocks, option A is correct.
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What is the atomic number of an atom that has 5 neutrons and 4 electrons
The atomic number is 4.
The atomic number of the given atom is equal to 4.
What is the atomic number?The atomic number (symbol Z) of a chemical element can be defined as the charge number of an atomic nucleus. For an ordinary atom, the atomic number is equal to the number of protons found in the nucleus of an atom of that element.
The atomic number helps to uniquely identify ordinary chemical elements. In an ordinary uncharged atom or neutral atom, the atomic number of that atom is also equal to the number of electrons.
For a neutral atom, the sum of the atomic number and the neutron number gives the atomic mass. The protons and neutrons have approximately the same mass. Atoms that have the same atomic number but different numbers of neutrons or different mass numbers are known as isotopes.
Given the number of electrons in the atom is 4. Therefore, the atomic number of that atom will be equal to 4.
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How did the atom model change
Answer:
Neil's Bohr improved Rutherford's model.
Explanation: I hope this helps! :)
Match the following properties with the type of property they are (chemical or physical) or the type of change the substance is undergoing (chemical or physical).
reacts with base-
smell-
color-
boiling point-
fruit rotting-
dissolving kool-aid powder-
reacts with water-
iron rusting-
water freezing-
1.
Chemical Property
2.
Physical Property
3.
Chemical change
4.
Physical change
Answer:
Chemical property
Iron rusting Fruit rottingPhysical property
Boiling point Water freezingChemical change
React with waterReact with basePhysical change
Color SmellScientist at the CDC (Center for Disease Control) in Atlanta, GA are currently developing and testing new treatments and vaccines for the coronavirus. What kind of research are they conducting?
Answer:
Applied research
Explanation:
The process of developing a new vaccine involves the use of known scientific theories to address specific problems. Here, the outcome of several basic research are put into use to arrive at a targeted outcome. This outcome/product can be continuously modified (if it shows early promise) until the desired effect is achieved and if no "promise" is discovered at critical points of this research, work on this theory (for this research) is suspended another theory is pursued.
This process (described above) in which scientists continuously develop new treatments and/or vaccines and continuously subject it to testing until the desired effect is achieved can be referred to as Applied research.
How do I convert 3.221×10^−3 mm to standard notation
Answer:
0.003221
Explanation:
When we multiply anything by 10 times a power, we follow the base 10 decimal system.
To convert 3.221 × 10⁻³ from scientific notation to standard notation, simply move the decimal place 3 places to the left:
3.221 × 10⁻³ = 0.003221
How many significant figures does 0.857610 have?
Answer: 6
Explanation:
Because it's 6 after the decimal
Consider a sealed glass bottle. If the bottle is thrown into a fire, what will happen to the bottle and why? Which law is the best explanation?
Answer:
Charles' Law
Explanation:
If a sealed container of gas were placed in a fire, the temperature and pressure of the gas would increase until the container broke or exploded. ... to volume when temperature is constant.
In the case when the bottle should be thrown into the fire so here Charles' Law should be applied.
What is Charles' Law?Charles's law is a statement where the volume should be occupied by a fixed amount of gas that should be directly proportional to its absolute temperature in the case when the pressure remains constant.
Since in the case when the sealed container of gas should be placed in the fire so here the temperature and the pressure should be increased till the break of the container.
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1. A 205 g sample of H20 at 25.0 °C is heated until the temperature reaches 75.0 °C. How many
Joules of heat were required to do this? (remember c = 4.184J/g • °C)
Answer:
i really dont know
Explanation:
byeeeeeeeeeeeee