Answer:
b
Explanation:
Which material is a heterogeneous mixture?
O A. A brass coin
B. Tap water
C. Vinegar
D. Soil
Answer:
D
Explanation:
Heterogeneous mixture is a mixture of non-uniform composition & in which the components can be easily identified
Answer:
Soil
Explanation:
Soil is made up of many things (therefore it's not pure) and does not appear to be uniform; it does not look the same throughout. Therefore it is heterogeneous.
Which is the Lewis structure for H3PO4?
::
i
H-Ö
0-H
ö
öz-ö-1
H
I
H
H-0–H
ô–P 6
Answer:
C. H:C:H:H
Explanation:
Follow these simple steps to correctly draw a Lewis dot structure: Add up the total number of valence electrons found in the entire compound. Draw the simple structure (skeleton structure) of the compound by connecting everything with single bonds only. Add electrons to all the noncentral atoms. Put any unused electrons on the central atom.
During chemical reactions__________are broken and___________to form
new substances with different properties, but mass is still_____________ .
Answer:
1st blank : Atoms
2nd blank : Reactants
I'm still trying to find the 3rd blank. I'll put it in comments if I find it
Explanation:
Hope this helps :)
Pls make brainliest :}
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13. An atom has 8 protons, 8 electrons, and 7 neutrons. What is the charge of the
atom and what type of ion is it?
Answer:
oxygen
Explanation:
a change in the composition of matter _____________ occurs during a chemical reaction.
Answer: During a chemical change, the composition of matter always changes
Explanation:
The atomic number equals blank of blank electrons
Answer:
The atomic number equals number of protons and electrons
This is true when an atom is in neutral state.
14. A gas in a 400 ml flask exerts pressure of 81.0 kPa at 25.0°C. If the gas
was in a 250 ml container at a pressure of 101 kPa, the temperature would be
a) - 124 °C
b) - 41.2°C
c) 20.0°C
d) 232 °C
Answer: B would be the correct answer
Explanation: You will need to use P1V1/T1=P2V2/T2
So
P1= 81.0kPa /101 =0.799atm
V1=0.4L
T1=25.0C +273.15K= 298.15K
P2= 101kPa /101 = 1atm
V2=0.25L
T2= ?
T2=P2V2T1/P1V1
(1.0atm)(0.25L)(298.15K)/(0.799atm)(0.4L) =233.22K-273.15=-39.92C
what is the source of the carbon plants use to make organic molecules?
Answer:
Carbon dioxide serves as the source of carbon,
Explanation:
What is the Golgi body made of?
O integral proteins
O large steroids
O RNA
O the same thing as the cell membrane
Explanation:
integral proteins...nns
Migration can best enhance the survival of individuals because it
Answer:
It can enhance survival because the animals for example birds are migrating to those places for high or increasing resources
Explanation:
a standard solution is made by diluting a small volume of stock solution. if 2.42 ml of stock solution is mixed with 7.55 ml of water, what is the concentration of the diluted solution? the stock solution concentration is 0.197 m.
Taking into account the definition of dilution, the concentration of the diluted solution is 0.063 M.
DilutionWhen it is desired to prepare a less concentrated solution from a more concentrated one, it is called dilution.
Dilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution at the same amount of solute.
In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.
A dilution is mathematically expressed as:
Ci×Vi = Cf×Vf
where
Ci: initial concentrationVi: initial volumeCf: final concentrationVf: final volumeConcentration of the diluted solutionIn this case, you know:
Ci= 0.197 MVi= 2.42 mLCf= ?Vf= 7.55 mLReplacing in the definition of dilution:
0.197 M× 2.42 mL= Cf× 7.55 mL
Solving:
(0.197 M× 2.42 mL)÷ 7.55 mL= Cf
0.063 M= Cf
In summary, the concentration of the diluted solution is 0.063 M.
Learn more about dilution:
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Balance the following equation:
C7H602 + 02 -- CO2 + H20
Answer:
Explanation:
2C7H6O2 + 15O2 → 14CO2 + 6H2O.
Question 116 g of sunflower oil is
used in a recipe. The density of the
oil is 0.925 g/mL. What is the volume
of the sunflower oil in mL?
Explanation:
Volume = mass ÷ density
= 116 g ÷ 0.925 g/mL
= 125.41 mL
A 116 g of sunflower oil of 0.925 g/mL has a volume of 125.41 mL.Is it _________
To view _______ eclipse without eve protection.
A.Unsafe, lunar
B.Safe, solar
C.Unsafe, solar
D.Unsafe new moon
Answer:
unsafe, solar
Explanation:
A lunar eclipse covers the moon which is safe to look at. New Moon, again is simply the moon. However, we should never look at the sun, eclipsed or not!
Answer:
C, it is unsafe to view solar
without eye protection
If you were able to magnify a penny down to the atomic level, what two
observations could you make about the atoms?
The two observations you would make about the atoms are
They are made up largely of empty spaceTheir mass is concentrated at the center called a nucleusThese observations were made by Ernest Rutherford in his model of the atom established in 1911, when he performed his gold foil experiment and observed the scattering angle of the alpha particles which led him to conclude that the mass of the atom was concentrated at the center.
Also, that most of the alpha particles also went through the gold foil suggested that the atom was made up basically of empty space.
So,
The two observations you would make about the atoms are
They are made up largely of empty spaceTheir mass is concentrated at the center called a nucleusLearn more about the atom here:
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Someone pls help me I will make you brain
ANSWER : I AND III
HOPE IT HELPED
is a paper clip homogeneous or heterogenous? substance or mixture? solution, colloid, suspension?
Explanation: It is an alloy, very probable, not homogeneous.
A metal paper clip is usually steel, an alloy of iron, carbon, and other elements in various amounts. A plastic paper clip is composed of a polymer, a very complex compound.
A paper clip is a Colloid
i guess this helped you pls mark me as brainliest
How would the electron configuration of nitrogen change to make a stable configuration?
It would lose four electrons.
It would gain three electrons.
It would gain two electrons.
It would lose five electrons.
Which quantity determines how two atoms bond?
the difference in the number of valence electrons
the difference in their electronegativities
their total number of valence electrons
the sum of their electronegativities
Which statement best explains why the elements in Group 18 do not have electronegativity values?
The elements do not have electrons.
The elements are too large.
The elements have filled valence levels.
The elements have only one electron shell.
Based on patterns in the periodic table, which ion has a stable valence electron configuration?
potassium (K) with a 1+ charge
magnesium (Mg) with a 1− charge
sulfur (S) with a 1− charge
fluorine (F) with a 1+ charge
Which chemical formula represents a polyatomic ion?(1 point)
Na+
Cl–
NaCl
ClO–
The answers to the questions are as follows;
It would gain three electronsThe difference in their electronegativities.The elements have filled Valence levelspotassium (K) with a 1+ chargeClO-Question 1:
How would the electron configuration of nitrogen change to make a stable configuration?Since Nitrogen has 5 Valence electrons, it needs 3 electrons to attain it's octet configuration. As such, it gains 3 electrons.
Question 2:
Which quantity determines how two atoms bond.The quantity which determines how two atoms bond is The difference in their electronegativities.
Question 3:
Which statement best explains why the elements in Group 18 do not have electronegativity values.This is because the elements have filled Valence levels.
Question 4:
Based on patterns in the periodic table, which ion has a stable valence electron configurationThe ion which has a stable Valence electron configuration is potassium (K) with a 1+ charge
Question 5;
Which chemical formula represents a polyatomic ion?The chemical formula which represents a polyatomic ion is; ClO-
An atom is electrically neutral when...
O The number of protons and neutrons are equal.
O The number of protons and electrons are equal.
O The number of neutrons and electrons are equal.
O The neutrons balance the protons and electrons.
Answer:
The number of protons and electrons are equal.
Explanation:
When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral.
how many electrons can occupy the 4p sublevel of a neutral atom of bromine
Answer:
6
Explanation
every p sublevel holds up to 6 electrons
so the 4p sublevel must hold up to 6 electonsr
Read that From picture and tell me the answer please
Answer:
1g Hydrogen
Explanation:
Getting to the equation:Calcium in water reacts vigorously to give a cloudy white Precipitate (compound) called Calcium hydroxide alongwith the evolution of Hydrogen gas.
[tex] \boxed{ \mathsf{Ca + H_2O \rightarrow Ca(OH)_2 + H_2}}[/tex]
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Balancing the equation:This reaction is not in it's balanced form! The number of atoms of Hydrogen on the left is 2 while that on the right is 4,I.e.,they're not equal.
Adding a 2 in front of H2O solves the problem by making the number of atoms of each element on both the sides equal.
[tex] \mathsf{Ca +2 H_2O \rightarrow Ca(OH)_2 + H_2}[/tex]
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Observations:Looking into the equation more carefully, we see:
1 atom of Calcium reacts with 2 molecules of water to give 1 molecule of Calcium Hydroxide alongwith 1 molecule of Hydrogen gas.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gram atomic and molecular massesMass of one atom of Calcium = it's gram atomic mass
= 40 g
Mass of one "molecule" of Hydrogen
= it's Gram molecular mass
= gram mass of one atom × number of atoms in one molecule
= 1 × 2
= 2 g
So,
according to our observation:
One atoms of Calcium gives one molecule of Hydrogen (during the particular reaction)
=> 40g of Calcium gives = 2g of Hydrogen
•°• 1 g of Calcium gives = [tex] \frac{2}{40} [/tex]
= [tex] \frac{1}{20} [/tex] g Hydrogen
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Answer:We're provided with 20g of Calcium,
=> 20g of Calcium gives = 20 × [tex] \frac{1}{20} [/tex] g H2
= 1 g H2
_______________
Hope this helps!
Please help I am stuck on this question
i think the answer is nervus cell because they work togtter to form the brain
HELPPPP PLEASE WILLLL GIVE BRIANLIESTTTT
We can use the formula M₁V₁ = M₂V₂ the total volume of water that will yield 0.800 M HCl. We can then subtract that from the initial volume to get how much water needs to be added.
Since M₁V₁ = M₂V₂ (starting mole× starting volume = end mole × end volume)
⇒ (5 mol)(20 mL) = (0.80 mol) V₂
100 mol/mL = 0.8 mol × V₂
⇒ V₂ = 100 mol/mL ÷ 0.8 mol
= 125 m
Since we began with 20.0 mL of water,
water needed to add = 125 mL - 20 mL = 105 mL
help plssssssssssssssss??
Answer:
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
Explanation:
Chemical change involves formation of new substances. Therefore, the correct answer is "Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form."
A field of many different species of wildflowers would be considered a(n) _____________.
a
organism
b
population
c
community
d
ecosystem
e
biome
f
biosphere
Answer:
That would be a community.
Explanation:
A field of many different species of wildflowers is considered to be a community.
What is community in biological terms?It is called biological community meaning an interacting group of various species sharing a common location.Factors which determine overall structure of community are number of species, abundance of each species,interaction among the species and community's ability to return to normal after a natural calamity.
Change of communities over a period of time is called as ecological succession.Each species in a community has its own characteristic niche . The niche includes all the interactions of the species with other members of the community.An ecosystem comprises of biological community together with its physical environment.
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The period of the vibrating string is 0.004 seconds. What is the frequency of the
standing wave?
Answer:4
Explanation:
Which statement accurately describes the bond that forms between carbon and oxygen to create carbon dioxide
Answer:
the bond that forms between carbon and oxygen to create carbon dioxide
A polar covalent bond
pls hurry
Which important law states that when elements are arranged by atomic number, similarities in chemical properties exist?
1)Periodic Law
2)Mendeleev's 1st law
3)Law of Atomic Structure
4)Theory of Periodic Succession
Answer:
plusses give me brainliest after this
The answer is: 1. periodic table
Ionization energy and electronegativity show similar trends in the periodic table. Describe these trends. What is the significance of the similarity of these trends?
Taking into account the definition of ionization energy and electronegativity, you can say that the significance of the similarity of these trends is that while electrons are more attracted to the nucleus (electronegativity), more energy is needed to extract an electron from a neutral atom (ionization energy).
Ionization energy
Electrons are held in atoms by their attraction to the nucleus, which means that energy is needed to remove an electron from the atom.
Ionization energy, also called ionization potential, is the necessary energy that must be supplied to a neutral, gaseous, ground-state atom to remove an electron from an atom. When an electron is removed from a neutral atom, a cation with a charge equal to +1 is formed.
The further away the electron is from the nucleus, the easier it is to remove it, that is, the less energy is needed.
In a group the atoms have the same electronic structure in the outermost shell. But when going down in the same group, the electrons find themselves in shells that are farther and farther away from the nucleus, being less and less attracted. The size of the atom increases as the number of electronic shells increases, increasing the atomic radius when descending in a group. But the electrons are farther from the nucleus, and the easier it will be to expel them. That is, its extraction from the atom is facilitated. So the ionization energy decreases when descending in a group. In other words, ionization energy is a function of atomic radius; the larger the radius, the less energy is required to remove the electron from the outermost orbital.
By increasing the atomic number of the elements of the same period, the nuclear attraction on the outermost electron increases, since the atomic radius decreases and the effective nuclear charge on it increases.
For this reason, in a period, as the atomic number increases, the ionization energy becomes greater.
ElectronegativityThe electronegativity of an element is defined as the relative ability of an atom to attract electrons from another atom to chemically bond and form a compound.
In other words, electronegativity is a measure of the attractive force that one atom exerts on the electrons of another when a chemical bond forms.
In the groups, the electronegativity decreases from top to bottom because the valence shell moves away from the nucleus and with this the attraction that the nucleus exerts on the valence electrons decreases.
In the periods, the electronegativity increases from left to right, because the number of electrons in the valence shell increases, so the attraction of other electrons increases to complete the valence shell and reach a stable state.
Similarityof the trendsThe significance of the similarity of these trends is that while electrons are more attracted to the nucleus (electronegativity), more energy is needed to extract an electron from a neutral atom (ionization energy).
Then, electronegativity is related to ionization energy in the following way: an atom with a high ionization potential has a high electronegativity. On the contrary, atoms with low ionization potential have small electronegativity.
Learn more about
electronegativity: brainly.com/question/14481608?referrer=searchResults brainly.com/question/21298480?referrer=searchResultsionization energy:brainly.com/question/16243729?referrer=searchResults brainly.com/question/11623163?referrer=searchResults brainly.com/question/1602374?referrer=searchResultswho is considered the father of the periodic table
Answer:
Dmitri Mendeleev
Explanation: