Who still uppppppp and boreddddd
Answer:
me
Explanation:
Which further observation led Mendeleev to create the periodic table
Answer:
Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
Explanation:
Express the difference of 7.69 and 4.0 using the correct number of significant digits:
3.7
3.70
3.6
0
3.69
Answer:
3.7
Explanation:
Significant figures:
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.007 in this number only one significant figure present which is 7.
Zero between non zero digits are consider significant such as 1004 consist of four significant figures.
The zeros at the right side such as 4500 are also significant. There are four significant figures are present.
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.
Now we will calculate the difference between 7.69 and 4.0.
7.69 - 4.0 = 3.69
In given values 4.0 have less number of decimal places thus result must have only one decimal places. So we would round the result.
3.7
A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass
Answer:
Mass = 0.000176 gram
Steps:
m = V × ρ
= 20 milliliter × 8.8 gram/cubic meter
= 2.0E-5 cubic meter × 8.8 gram/cubic meter
= 0.000176 gram
Explanation:
4. Describe the arrangement of the electrons on each energy level.
Answer:
Explanation:
If the energy of an atom is increased, an electron in the atom gets excited. To go back to its ground state, the electron releases energy. The energy of the light released when an electron drops in energy level is the same as the difference in energy between the two levels.
Viewed simply, electrons are arranged in shells around an atom’s nucleus. Electrons closest to the nucleus will have the lowest energy. Electrons further away from the nucleus will have higher energy. An atom’s electron shell can accommodate 2n2 electrons (where n is the shell level).
In a more realistic model, electrons move in atomic orbitals, or subshells. There are four different orbital shapes: s, p, d, and f. Within each shell, the s subshell is at a lower energy than the p. An orbital diagram is used to determine an atom’s electron configuration.
There are guidelines for determining the electron configuration of an atom. An electron will move to the orbital with lowest energy. Each orbital can hold only one electron pair. Electrons will separate as much as possible within a shell.
In an atom, electrons are arranged in shells that surround the nucleus, with each successive shell moving further away from the nucleus.
What is energy level?In physics, an energy level is any discrete value from a set of total energy values for a subatomic particle confined by a force to a limited space or for a system of such particles, such as an atom or a nucleus.
Energy levels are fixed distances from an atom's nucleus where electrons can be found. Electrons are tiny, negatively charged particles that move around an atom's positive nucleus. The steps of a staircase represent energy levels.
Around the nucleus, electrons are arranged in different shells. Each successive shell can only hold so many electrons. First, the innermost shell is filled. This shell can only contain two electrons.
Thus, this way, the electrons are arranged.
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What is the mass, in grams, of 0.450 moles of Sb?
Answer:
54.9 g
Explanation:
0.450 mol x 122g/mol
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, 54.9 g is the mass in grams of 0.450 moles of Sb.
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.
Average atomic mass = (mass of first isotope× percent abundance of first isotope)+(mass of second isotope× percent abundance of second isotope)
Mass of Sb= number of moles of Sb ×Molar mass of Sb
=0.450 mol x 122g/mol
=54.9 g
Therefore, 54.9 g is the mass in grams of 0.450 moles of Sb.
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The quantum mechanical model...
a
describes electrons as moving through specific circular orbits, and not staying in one place.
b
places electrons in fixed positions, not moving through specific orbits or orbitals.
c
describes electrons as moving anywhere in the atom, not specific circular orbits.
d
describes electrons as moving through cloud-like orbitals, not specific circular orbits.
identify the elements given the orbital diagrams listed below.
Answer:
See explanation.
Explanation:
1. There are 8 electrons. Elements that end with 2p orbitals are in the 2nd period (aka row) of the periodic table. Elements that have 4 electrons in 2p are in the 16th group (aka column) (column 16 may also be referred to as 6A) of the periodic table. So looking at row 2, column 16, we can see that the first diagram is of O, Oxygen.
2. 8 electrons. This is the same diagram as the one above.
3. 13 electrons. Elements ending with 3p are in period 3. Elements with 1 valence electron in a p orbital are in group 13 (aka group 3A).
4. 7 electrons. We already know 2p is period 2. 3 valence electrons in a p orbital means that it is in group 15/group 5A.
I did not write the answers for #3 and 4 but they can be easily found on a periodic table with the info I gave.
The elements given the above orbital diagrams are as follows:
Oxygen
Oxygen
Aluminum
Nitrogen
In first case,
There are total 8 electron and the electronic configuration is 1s2 2s2 2p4. The element which end up with 2p configuration belongs to 2nd period. It have four electron in their outermost shell so, it belongs to 16th group, So the element is Oxygen.
In the same way we will find the elements for rest of the cases.
Thus, we reach to the conclusion that the elements given the above orbital diagrams are as follows:
Oxygen
Oxygen
Aluminum
Nitrogen
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what is 1.23 x 10^-3 in standard notation
Answer:
=0.00123
Explanation:
Look at the attachments below
Hope this helps (:
Answer:
0.00123
Explanation:
Standard notation is the normal way of writing numbers. Examples include 1, 2, and 10. The number 1.23 x 10^-3 is written in scientific notation. The decimal goes after the first nonzero integer and it is multiplied by a power of 10. The power or exponent attached to the 10 tells you how many places over you need to move the decimal to get back into scientific notation. Examples include 1.00 x 10^2 (representing 100 in standard form because you would move the decimal two places to the right.), 2.0 x 10^1 (representing 20 in standard form because you would move the decimal one place to the right), and 3.0 x 10^-4 (representing 0.0003 in standard form because you would move the decimal four places to the left since it is a negative exponent).
The negative (-3) exponent in 1.23 x 10^-3 indicated to move the decimal three places to the left. If it was positive, you would move it three places to the right.
In 1.23 x 10^-3 move the decimal to the left 1 place to get:
0.123
two places to get:
0.0123
and a third place to get:
0.00123
The final answer is 0.00123
Which unit would you use to measure the mass of a student desk?
Answer:
b and then c
thanks for the brainly points
Identify the mineral that can have the composition of KMg3AlSi3O10(OH)2
Answer:
Phlogopite
Explanation:
It is a member of mica group family of phyllosilicates mineral. It is the magnesium endmember of the biotite stable - the chemical formulation KMg3AlSi3O10 (F, OH) 2.
You check the air pressure in your car tires on Monday morning and the pressure
reads 765 mmHg. A cold front drops the temperature considerably overnight. You
check your tire pressure Tuesday morning and the pressure reads 740 mmHg.
Using what you've learned about the properties of gases, what causes this change
in pressure?
Can you help me please
what are your steps to this from the lesson
The bright red line from the emission spectrum of hydrogen has a wavelength of 657 nm. What is the energy, in joules, of a single photon of this light? 4.35 x 10–40 J 3.03 x 10–28 J 3.03 x 10–19 J 4.56 x 1014 J
Answer:
3.03 × 10^-19 J
Explanation:
The energy, E, of a photon of light can be calculated by using the formula:
E = hv
Where; E is energy in Joules,
h is Planck's constant {6.626×10^−34J}
v is frequency of light
For this question, the wavelength (λ) is given, not the frequency (v).
Hence, we use;
v= c/λ
Where v= frequency, c= speed of light (3×10^8m/s), λ= wavelength (657nm)
657nm = 657 × 10^-9m
v = 3×10^8/657 × 10^-9
v = 3/657 × 10^(8--9)
v = 0.00456 × 10^17
v = 4.56 × 10^14
Since frequency (v) = 4.56 × 10^14;
E = hv
E = 6.626×10^−34 × 4.56 × 10^14
E = 30.21 × 10^(-34+14)
E = 30.21 × 10^-20
E = 3.021 × 10^-19
Therefore, the energy of the photon of light is 3.02 × 10^-19 J
Two people are pulling on a rope, like in the picture below. The person on the left pulls at 5 N and the person on the right pulls 5 N. What is the net force on the rope?
Answer:
The net force is 0
Explanation:
because both people on either side are pulling the rope with the same force
How many moles are in 12.6 grams of K2S?
You have an empty milk container, and you close the cap on the container. Do the particles of air that you trapped inside the container have mass? Explain how you know.
Answer:
Yes the air particles have mass
Explanation:
Air is mater: it has weight and occupies space. For it to have weight, it has to have a mass. The mass would however be determined by how much volume of air is trapped in the container, but nevertheless, the mass of the air can be obtained.
We also notice that if the container is "popped", the mass of air escapes through one way by the weight exerted on it.
I hope this was helpful.
Answer:
Yes the air particles have mass
Explanation:
You can tell that if the container is pooped open the mass of air escapes
when Lithium forms an ionic compound with carbonate, how many of each ion is needed?
Answer:
Two Lithium ions and one carbonate ion
Explanation:
Let us look at this equation;
Li2CO3(s) ------->2Li^(aq) + CO3^2-(aq)
We can see that each unit of Li2CO3 has two lithium ions and one carbonate ion.
Let us not forget that Li has a valency of 1 while carbonate ion has a valency of 2. Exchange of valencies gives the final formula of the compound.
Answer:
Two Lithium ions and one carbonate ion
Explanation:
In which situation is it better to have low friction?
Choose the correct answer.
a skydiver uses a parachute
a student walks down a hallway
a ladder leans against the wall
a hockey puck slides toward the goal
Answer: D- a hockey puck slides toward the goal
Explanation:
It needs to be able to slide easily and thats the correct answer on the test
A
Carpet is beaten to
beaten to remove dust
Answer:
It's Clean?
Explanation:
Determine the amount of energy (heat) in Joules and Kcal required to raise the temperature 0f 98.5 grams water from 37.0 0C to 75.0 0C.
Answer:
15660.712J
Explanation:
Q = m × c × del T
Q(energy) = ?
m (mass) = 98.5g
c = 4.184J
del T = 75-37 = 38 °C
Q = 98.5 × 4.184 × 38
Q = 15660.712 J
An unknown substance has a volume of 2 cm3 and a mass of 38.6 grams.
What is the density of the sample?
Answer:
The answer is 19.3 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{38.6}{2} \\ [/tex]
We have the final answer as
19.3 g/cm³Hope this helps you
If a wave of red light has a wavelength of 6.7 x 10-7 m, will the frequency of the red wave be high or low?
Answer:
Its high
Explanation:
Becuase if u times it what do u get
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
ctivity
Answer:
A) form when lava and magma cool
please give me brainliest :p
God bless!
Answer:
A: form when lava and magma cools
Explanation:
Got it right on Edge 2020 :)
whats the lewis dot diagram for calcium
Draw the Lewis dot structure for each atom of the compound to show how many valence electrons are present in each atom. For example, the calcium atom in calcium chloride, CaCl2, has two valence electrons, and the chlorine atoms have seven valence electrons each.
Plowing is an example of what Energy?
a. Kinetic Energy
b. Potencial Energy
Answer:
mechanical or kinetic eg hammer and nails
Write a complete, balanced chemical equation where tin metal reacts with aqueous hydrochloric acid to produce tin(II) chloride and hydrogen gas. Include states.
From the equation, which element is oxidized, and which element is reduced?
Answer:
1. The balanced equation is given below:
Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)
2a. H is oxidized.
2b. Sn is reduced.
Explanation:
1. Balanced equation for the reaction between tin (Sn) metal and aqueous hydrochloric acid (HCl) to produce tin(II) chloride (SnCl₂) and hydrogen gas (H₂).
This is illustrated below:
Sn (s) + HCl (aq) –> SnCl₂ (aq) + H₂ (g)
There are 2 atoms of Cl on the right side and 1 atom on the left side. It can be balance by putting 2 in front of HCl as shown below:
Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)
Now, the equation is balanced
2. Determination of the element that is oxidize and reduced.
This can be obtained as follow:
We shall determine the change in oxidation number of each element.
NOTE:
a. The oxidation number of H is always +1 except in hydrides where it is –1.
b. The oxidation state of Cl is always –1.
Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)
For Tin (Sn):
Sn = 0
SnCl₂ = 0
Sn + 2Cl = 0
Cl = – 1
Sn + 2(–1) = 0
Sn – 2 = 0
Collect like terms
Sn = 0 + 2
Sn = +2
Therefore, the oxidation number of Tin (Sn) changes from 0 to +2
For H:
H = +1
H₂ = 0
The oxidation number of H changes from +1 to 0
For Cl:
Cl is always –1. Therefore no change.
Summary:
Element >>Change in oxidation number
Sn >>>>>>>From 0 to +2
H >>>>>>>>From +1 to 0
Cl >>>>>>>No change
Therefore,
Sn is reduced since its oxidation number increased from 0 to +2.
H is oxidized since it oxidation number reduced from +1 to 0
The balanced chemical equation for the reaction is
Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)
and the element that oxidized is tin (Sn) while the element that is reduced is hydrogen (H)
The balanced chemical equation for the reaction where tin metal reacts with aqueous hydrochloric acid to produce tin(II) chloride and hydrogen gas is
Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)
From the equation,
The element that is oxidized is tin (Sn), because the oxidation state of Sn increased from 0 to +2
The element that is reduced is hydrogen (H), because the oxidation state of H decreased from +1 to 0.
Hence,
The balanced chemical equation for the reaction is
Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)
and the element that oxidized is tin (Sn) while the element that is reduced is hydrogen (H).
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8. Describe how crystals of copper sulphate are prepared.
Answer:
Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.
Hope it helps
Technetium-104 has a half-life of 18.0 minutes. How much of a 165.0 g sample remains after 126 minutes?
Answer:
1.28g
Explanation:
honestly just put it a half life caculator i couldnt tell you how to do it if my life depended on it ♂️
during recycling, ground glass is melted under light heat and poured into molds. which type of change occurs as the glass melts?
The state change occurs when the glass melts.
What are different states of matter?The matter is anything that has mass and occupies space.
The different states of matter are solid, liquid, gas, and plasma.
The properties of the different types of matter can be understood by looking at the arrangement of molecules.
When a solid substance is heated beyond its melting point, it changes its state from solid to liquid.
When liquid is heated beyond its vaporizing point, it changes its state from liquid to gas.
Solids are closely packed and have a definite shape and size.
Liquids are loosely packed and take up the space of the container.
Gas has high intermolecular spacing and the gases are not rigid.
Ground glass is melted under light heat and poured into molds.
Recycling glass involves changing the state of glass from solid to liquid state.
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