Answer:
D.Magnesium
Explanation:
Cause imma nerd
A student has a sample of solid calcium. It is shiny and metallic looking. He squeezes a pipet of concentrated sulfuric acid onto the calcium. Bubbles are produced and the calcium appears to disappear. The test tube gets hot. What kind of change occurred?
Answer:
Physical change
Explanation:
There are two types of changes: physical change and chemical change. Physical change is defined as the change that changes the physical appearance of the substance and do not affcet the chemical composition of the substance whereas chemical change causes changes in the chemical composition of the susbstance.
The given example shows physical change because solid calcium undergoes sublimation. process in which a solid substance changes into gaseous phase directly without undergoing liquid phase.
Hence, the correct answer is "Physical change".
Is the freezing point of this 5??
Please correct my mistake if it isn't.
Answer:
yes
Explanation:
Answer:
yes
Explanation:
you're smart have a nice evening
12. A 100.00-gram sample of naturally occurring boron
contains 19.78 grams of boron-10 (atomic mass =
10.01 atomic mass units) and 80.22 grams of
boron-11 (atomic mass = 11.01 atomic mass units).
Which numerical setup can be used to determine the
atomic mass of naturally occurring boron?
A) (0.1978)(10.01) + (0.8022)(11.01)
B) (0.8022)(10.01) + (0.1978)(11.01)
C) (0.1978)(10.01)/(0.8022)(11.01)
D) (0.8022)(10.01)/(0.1978)(11.01)
It’s A) (0.1978)(10.01) + (0.8022)(11.01)
Relative and average atomic mass both describe properties of an element related to its different isotopes. Out of these two Relative atomic mas is more accurate. Therefore option A is correct option.
What is mass?Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes. It can be calculated by multiplying mass of a isotope to natural abundance of that isotope.
Mathematically,
average atomic mass= ∑(relative abundance x mass of isotope)
average atomic mass boron= (relative abundance boron-10 x mass of isotope boron-10)+(relative abundance boron-11 x mass of isotope boron-11 )
average atomic mass boron=(0.1978)(10.01) + (0.8022)(11.01)
Therefore option A is correct option.
To learn more about mass, here:
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It is found that after 24!hours 1/8 of the mass of a sample of a radio-active isotope remains What is the half-life of this isotope?
Answer:7.72 years
Nuclear half-life expresses the time required for half of a sample to undergo radioactive decay.
Explanation:
0.01 = 67.0 ×[tex](\frac{1}{2}) ^{\frac{98.0} {1/2 } }[/tex] [tex]\frac{0.01}{67.0}[/tex] = 0.000149=[tex](\frac{1}{2}) ^{\frac{98.0} {1/2 } }[/tex]
[tex]^{\frac{98.0} {1/2 } }[/tex] =log[tex]_{0.5}[/tex] (0.000149)=12.7
[tex]^{\frac{98.0} {1/2 } }[/tex]=7.72 years
Hope this helps have a great day/afternoon :)
Between Na and Na+ which has larger size
Answer:
Na+ is smaller than Na because, it has given away one electron because of which the electron shielding gets stronger due to more protons and less electrons. Whereas, Cl- is larger than Cl because it has gained an extra electron and so, the no.07/12/2010
Explanation:
5. an atom that has lost or gained an electron and has become charged
A.ion
B. proton
C. ionic bond
D. compound
Answer:
It would be compound.
Explanation:
It is this way because if it adds another proton it becomes more positive that nuetral, and if you add an electron it just makes the atom more dense. That is why the answer is compound. Hope this helped :)
How many grams are in 1.98 x 1024 formula units of NaCl?
Answer:
There are 2027.52 formula units of NaCl
Explanation:
plz mark me brainlest
8. What is Planck's law?
O F = hm
O F = MA
O E = hf
O E = mc (squared)
Answer:
O E = hf
Explanation:
which of the following molecules has only two non binding pairs (long pairs) of electrons in its lewis structure?
a)O2
b)CH4
c)NH3
d)H2s
Explanation:
NH₃ has only two non-binding pairs (lone pairs) of e⁻ in it's Lewis structure.
••
H—N—H
|
H
Therefore,
C is correct. ✔
what acts as a buffer for seawater ?
Answer:
The bicarbonate and carbonate ions.
Explanation:
Probably not he answer your looking for though. So, CO2.
The main goal of science is to
Answer:
The goal of science is to learn how nature works by observing the natural and physical world, and to understand this world through research and experimentation.
Explanation:
PLEASE ANSWER
A train travels 200 miles at an average speed of 50 miles per hour. How long does it take the train to travel this distance?
What happens to the tape at the closer markers compared to the markers that are further away?
what are the 3 subatomic particles of the atom? What are their corresponding charges and locations within the atom?
Answer:
Protons, neutrons, and electrons are the three main subatomic particles found in an atom.
Explanation:
the negatively charged electrons can be found around the nucleus in an electron cloud.
The volume of an unknown liquid is shown in the graduated cylinder. The mass of the liquid is 105 grams.
What is the density of the unknown liquid?
A 3500 g/mL
B .33 g/mL
C 3.0 g/mL
D 3.3 g/mL
Answer:
the answer is c
Explanation:
Math and science skills
Please answer
1.
|Predict|
2.
|Use variables|
3.
|Plan and conduct investigations|
4.
Draw conclusions
5.
Hypothesize
6.
Measure
7.
Classify and order
8.
Record and display data
9.
|Use time and space relationships|
10.
Use numbers
Answer:6
Explanation:
Why the noble gases are found in small amounts in the earth's atmosphere?
Answer:
They have completely filled outermost shell
Explanation:
The noble gases are the rarest and occur in trace amounts in the atmosphere because they have completely filled outermost and this makes them unreactive with other elements.
Elements become abundant as they combine with other species to form compounds.
Noble gases on the other hand have a high level of stability and do not readily combine with other species.
Some of these gases are :
Helium
Neon
Argon
Krypton
Xenon
Radon
They have very high ionization energy and very low electron affinity and so will not readily react.
Find the percent of oxygen in CaClO3)2 Show your work
19. Who was the first female astronomer
A.Aristotle
B.En Hedu’Anna
C.Archimedes
D.Plato
Answer: A.En Hedu'Anna
Answer:
En Hedu’Anna!
Explanation:
during chemical reaction do atoms change into a new substance
true or false
Answer:
t
Explanation:
because for atoms to change they have to have some kind of chemical action to get new life
A hypothesis is ______ to explain a set of observations.
1 one possible way
2 the correct method
3 a factual statement
4 a set of data
Answer:
1
Explanation:
one possible way its just a theory of what the answer could be
Answer:
3-a factual statement
Explanation:
A hypothesis is a factual statement to explain a set of observations.
The maximum amount of statie friction between this chair
and the floor is 175 N.
Which action would cause the chair to move to the left?
A. Applying 100 N of force to the chair from the left
B. Applying 200 N of force to the chair from the left
O c. Applying 200 N of force to the chair from the right
O D. Applying 100 N of force to the chair from the right
Answer:
C
Explanation:
A p ex
TIME REMAINING
58:36
The electron configuration for Helium (He) is shown below.
1s2
Which diagram shows the correct distribution of electrons in the electron shells of a helium atom?
Answer:
'*:*'
Explanation:
I know this looks weird, but
'= electron
*:* equals the nucleus, so 2 protons and 2 neutrons
and then '=electron
It's how many atoms are in two water molecules (H2O)?
Answer:
The chemical formula for water is H2O which means that every molecule of water has 2 atoms of hydrogen (H) and one atom of oxygen (O). Here comes the key part. From the Periodic Table of Elements, one sees that one mole of hydrogen atoms weighs 1 gram while one mole of oxygen atoms weighs 16 grams.
Explanation:
:)
The number of atoms present in two water molecules is 6 atoms. 4 hydrogen atoms and 2 oxygen atoms.
What are atoms?Atoms are the basic unit of a substance. An atom is made of a nucleus, protons, neutrons and electrons. Different atoms combines to form a molecule and molecules combines to form compounds.
Water has the formulas H₂O, thus one molecule of water contains 2 hydrogen and one oxygen. Therefore, two molecules of water that is (H₂O)₂ have 4 hydrogen and 2 oxygens thus, a total of 6 atoms.
Hence, the number of atoms present in two molecules of water is 6.
To learn more about no. of atoms, refer the link below:
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Select the correct answer from each drop-down menu.
Why do some transition metals have multiple oxidation states?
Transition metals have multiple oxidation states because of their (a. completely filled b. partially filled c. empty) (s, p, d, or f) sublevel.
Answer:
because of energy difference between (n1)d and ns orbitals (sub levels) and involvement of both orbital in bond formation
Explaination:
the reason is that there is a difference in energy of orbitals of an atom of transition metal, so there (n1)d orbitals and there ns orbitals both make a bond and for this purpose they lose an electron that is why both sublevels shows different oxidation state.
Hope this helped you
Transition metals have multiple oxidation states because of their partially filled orbitals . Thus option b is correct.
What are transition metals?Transition metals are defined as essentially, a configuration attended by reactants during complex formation, as well as the reaction coordinates.
It can also be defined as a very short-lived atomic configuration at a reaction-energy diagram's local energy maximum.
Transition metals are best defined as an element with a partially filled d sub-shell on its atom or that can give rise to cations with an incomplete d sub-shell.
Transition state is defined as a chemical reaction is defined as a certain configuration along the reaction coordinate.
Oxidation state is defined as the total number of electrons that have been deleted or added to an element.
It can also be defined as an atom's charge if all of its links to other atoms were entirely ionic.
Thus, transition metals have multiple oxidation states because of their partially filled orbitals . Thus option b is correct.
To learn more about transition metals, refer to the link below:
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A chemical equation is balanced if there are ______ ______ of each kind of ______________________ on both sides of the equation.
If each side of the equation has the same number of atoms of a given element, that element is balanced. If all elements are balanced, the equation is balanced. So your sentence should look like this:
A chemical equation is balanced if there are equal atoms of each kind of element on both sides of the equation.
sexual reproduction helps to increase
a. the number of offspring
b. genetic variation
c. genetic mutations
Answer:
a. the number of offspring would be ur answer pls make me brainliest
4. Which elements would have similar properties to potassium?
A. Lithium and Sodium
B. Bromine and Krypton
C. Calcium and Scandium
D. Cobalt and Rhodium
Answer:
The answer is A. Lithium and Sodium
Explain what intermolecular forces are, and how they are easily overcome.
Explanation:
Intermolecular forces are forces that exist between two or more molecules and they can be overcome at high temperatures.
A student found the mass of a brick: 50 grams. The volume was 10 cubic centimeters. If the student had 5 bricks, what would be the total density?
Answer:
The answer is 5 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
The mass of one brick is 50 g
the volume of one brick is 10 cm³
Since the student had 5 bricks
Total mass = 5 × 50 = 250 g
total volume = 5 × 10 = 50 cm³
So the total density is
[tex]density = \frac{250}{50} = \frac{25}{5} \\ [/tex]
We have the final answer as
5 g/cm³Hope this helps you