Answer:
B. A mixture has different properties throughout; a pure substance has the same properties throughout
Explanation:
We have two classes of substances which are pure and impure substances.
Pure substances are elements and compounds
Impure substance are simply mixtures.
Mixtures have the following properties;
Their composition is indefinite i.e. they consist of two or more elements and or compounds in any proportion by mass. Constituents retain their identities i.e. physical properties are retained. Constituents react differently to changed conditionsThey can easily be separated by physical methods.Use scientific notation to express the number 355000 to:
1) one significant figure
2) two significant figures
3) three significant figures
4) four significant figures
5) six significant figures
Answer:
1) 4*10^5
2) 3.6*10^5
3) 3.55*10^5
4) 3.550*10^5
5) 3.55000*10^5
Explanation:
1) 4 x [tex]10^5[/tex]
2) 3.6 x [tex]10^5[/tex]
3) 3.55 x [tex]10^5[/tex]
4) 3.550 x [tex]10^5[/tex]
5) 3.55000 x [tex]10^5[/tex]
What is scientific notation?A number is written in scientific notation when there is a number greater than or equal to 1 1 11 but less than 10 10 1010 multiplied by a power of 10 10.
Significant figures are the number of digits in a value, often a measurement, that contributes to the degree of accuracy of the value.
1) 4 x [tex]10^5[/tex]
2) 3.6 x [tex]10^5[/tex]
3) 3.55 x [tex]10^5[/tex]
4) 3.550 x [tex]10^5[/tex]
5) 3.55000 x [tex]10^5[/tex]
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Atoms are the
piece of an
Answer:
Our current model of the atom can be broken down into three constituents parts – protons, neutron, and electrons. Each of these parts has an associated charge, with protons carrying a positive charge, electrons having a negative charge, and neutrons possessing no net charge.
There are 20 mice in a 5 m2 field ecosystem. The population density of mice is _____.
20 per m 2
5 per m 2
25 per m 2
4 per m 2
Answer:
4per m 2
20 mice divided by 5 so it will be 4 per m 2
7. Which of the following pairs of elements is most likely to form an ionic
compound?
b. potassium and neon
c. barium and aluminum
a. oxygen and fluorine
d. lithium and bromine
Answer:
not sure if this us right but oxygen and fluorine? I learned chem but I forgot about it kinda sorry
I need to know the weighted average please!
Answer:
63.5456 amu
Explanation:
[tex]0.6917*62.9296+0.3083*64.9278= 63.5456\ amu[/tex]
What is the mass of 8.8 x 10^22 of magnesium
Answer:
0.05
moles
Explanation:
In a mole of any substance, there exist
6.02⋅1023
units of that substance.
So here, we got:
3.01⋅1022Mg atoms⋅1mol6.02⋅1023M gatoms=0.05mol
is na2o a element or compound
Answer:
Its a compound :PP
Explanation:
have a good day
Answer:
Compound
Explanation:
If repeated measurements agree closely but differ widely from the
accepted value,
these measurements are
neither precise nor accurate.
accurate, but not precise.
both precise and accurate.
precise, but not accurate.
Answer:
precise but not accurate
Explanation:
precision is getting the same answer over and over, but not necessarily correct.
accuracy is getting the exact, or VERY close to exact, value
since the question states the repeated measurements agree closely it is saying it is precise, but when it says differ widely from accepted value it is saying NOT accurate.
FeO+ PdF2 ---> FeF2+PdO balance please worth 50 points
Answer: FeO
Explanation:
Answer:
This is not worth 50 points liar
Explanation:
The volume of a gas with an initial pressure of 380 mmHg atm increases from 5.0 L to 8.0 L. What is the final pressure of the gas, in atm, assuming no change in moles or temperature?
A) 238 atm
B) 2.4 atm
C) 0.31 atm
D) 0.80 atm
E) 8.0 atm
Answer:
0.31 atmExplanation:
The new pressure can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new pressure
[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]
From the question
760 mmHg = 1 atm
380 mmHg = 0.5 atm
We have
[tex]P_2 = \frac{0.5 \times 5}{8} \\ = 0.3125[/tex]
We have the final answer as
0.31 atmHope this helps you
Answer please thanks
Answer:
7. A. ee
8. Genotypes in which the dominant gene must show: Both A & B
9. Genotypes in which the recessive genes must show: A. aa
What is nuclear fusion what role does it play in the sun
Answer:
Nuclear fusion is when two atomic nuclei combine and form one nucleus. Nuclear fusion generates all of the Sun's energy. Inward pulling by the Sun's gravity is counteracted by outward pushing by the Sun's nuclear fusion; this balance keeps the sun from collapsing or exploding.
Explanation:
Answer:
it converts mass into energy and hydrogen into helium.
Explanation:
Nuclear fusion, the source of all the energy so generously radiated by the Sun
List three things, other than the name, symbol, atomic number, and average atomic mass, you can discover about an element using the periodic table in Figure 6.9.
Answer: State of matter, Subcategory in the metal-metalloid-nonmetal trend, and electrons per shell.
Explanation:
What is the molar mass of h2
Answer:
The answer is one
Explanation:
I will just type any rubbish here bcuz my answer should be more than 20 words..... Just know the answer is 1
You have 3.00 L of a 3.12 M solution of NaCl(aq) called solution A. You also have 2.00 L of a 2.00 M solution of AgNO3(aq) called solution B. You mix these solutions together, making solution C.
Calculate the concentration (in M) of Ag+ ions in solution C.
Answer:
[tex]M=0.8M[/tex]
Explanation:
Hello!
In this case, since the presence of silver ions is in AgNO3 only, we can compute their moles by using the volume and concentration of the corresponding salt:
[tex]n_{Ag^+}=2.00L*2.00\frac{mol}{L}=4molAg^+[/tex]
Next, since the total volume of solution C is 5.00 L, the required concentration of silver ions turn out:
[tex]M=\frac{4.00mol}{5L} =0.8M[/tex]
Best regards!
Using the data below, calculate the enthalpy for the combustion of C to CO
C(s) + O2(g)--> CO2 (g) ΔH1 = -393.5 kJ
CO(g) + 1/2O2(g) -->CO2(g) ΔH2= -283.0kJ
Target: C(s) + 1/2O2(g) --> CO(g) ΔH3=??
Group of answer choices
Answer:
ΔH3 = -110.5 kJ.
Explanation:
Hello!
In this case, by using the Hess Law, we can manipulate the given equation to obtain the combustion of C to CO as shown below:
C(s) + 1/2O2(g) --> CO(g)
Thus, by letting the first reaction to be unchanged:
C(s) + O2(g)--> CO2 (g) ; ΔH1 = -393.5 kJ
And the second one inverted:
CO2(g) --> CO(g) + 1/2O2(g) ; ΔH2= 283.0kJ
If we add them, we obtain:
C(s) + O2(g) + CO2(g) --> CO(g) + CO2 (g) + 1/2O2(g)
Whereas CO2 can be cancelled out and O2 subtracted:
C(s) + 1/2O2(g) --> CO(g)
Therefore, the required enthalpy of reaction is:
ΔH3 = -393.5 kJ + 283.0kJ
ΔH3 = -110.5 kJ
Best regards!
Which one of the following
statements about the following
reaction is false?
CH4(g) + 202(g) → CO2(g) +
2H2O(g)
Answer:
5
Explanation:
How many moles are in a sample of 4.57 x 1024 atoms of neon (Ne)?
a.7.59 mol Ne
b.27.5 mol Ne
c.91.4 mol Ne
d.151 mol Ne
Answer:
A 7.59 mol Ne
Explanation:
The number of moles of Ne in a sample of 4.57 x 10²⁴ atoms of neon (Ne) are 7.59 mol of Ne. Hence Option (A) is the correct option. It can be solved with the help of Mole concept.
What is Mole concept ?The mole, symbol mol, is the SI base unit of amount of substance.
The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample.
n = given number / Avogadro's number
= 4.57 x 10²⁴ / 6.022 x 10²³
= 7.59 mol of Ne
Therefore, The number of moles of Ne in a sample of 4.57 x 10²⁴ atoms of neon (Ne) are 7.59 mol of Ne. Hence Option (A) is the correct option. It can be solved with the help of Mole concept.
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How many molecules of glucose (C6H12O6,M=180.18g/mol) are contained in 144mL of 0.280 M glucose solution?
Volume of Glucose solution = 144 mL OR 0.144 L
Molarity of Glucose solution = 0.280 M
Number of moles of Glucose in the solution:From the definition of Molarity, we know that:
Molarity = number of moles / volume(in L)
in this equation, multiplying both sides by Volume, we get:
number of moles = Molarity*Volume(in L)
replacing the variables
Number of moles = 0.280*(0.144L)
Number of moles = 0.04
Number of Molecules in the solution:
We know that:
Number of molecules = Number of Moles * Avogadro's number
Number of molecules = 0.04 * 6.022 * 10²³
Number of molecules = 0.24088 * 10²³
Number of molecules = 2.4088 * 10²²
Therefore, there are 2.4088 * 10²² molecules of Glucose in the given solution
35. Which subatomic particle has almost no mass relative to the others: the proton, the neutron or the electron?
Answer:
electron
Explanation:
it has very little mass
Writing Chemical Equations
Write and balance the equation showing the reaction between lead (II) sulfide and carbon monoxide to form lead metal and carbon dioxide.
Answer:Gaseous C4H8 + oxygen gas ---> carbon dioxide + water
C4H8(g) + 6O2(g) ---> 4CO2(g) + 4H2O(g)
Not the one u want but its similar so u can get an idea of what the one u want is like
Enter a numerical expression that represents the sum of u squared and 9, multiplied by eleven
Answer:
11(u² + 9)
Explanation:
The problem is to write a numerical expression for the statement given;
sum of u squared and 9, multiplied by eleven
Variable given = u;
u squared = u²
Sum;
u² + 9
multiplied by 11;
11(u² + 9)
Which type of reaction is NaCl + AgNO3 → NaNO3 + AgCl?
synthesis
decomposition
oxidation
replacement
Answer:
replacement
Explanation:
Please help !!!
The atomic number of sodium is 11. How many neutrons does an isotope with a mass number of 22 have ?
Answer:
11
Explanation:
Which statement about the surface of the moon is true?
o There is water and air, but no life on the moon's surface.
O There is no air, wind, liquid water or life on the moon's surface.
There are liquid seas on the moon's surface.
It is very windy on the moon's surface.
Answer:
There is no air, wind, liquid water or life on the moons surface.
Explanation:
Answer:
ok i know it wont help now bc this was in 2020 but i did this on my lessons and its: There is no air, wind, liquid water, or life on the moon's surface.
Explanation:
i got all the right except the last one
Write the charge balance for an aqueous solution of arsenic acid, H3AsO4, in which the acid can dissociate to H2AsO24 , HAsO24 2, and AsO34 2. Look up the structure of arsenic acid in Appendix G and write the structure of HAsO24 2.
Answer:
Kindly check the explanation section.
Explanation:
When the Arsenic acid,H3AsO4 is put in water it dissociates to form or give out 1 proton, 2 protons or 3 protons that is 1H^+, 2H^+ and 3H^+. Check the equation showing the dissociation reactions as given below;
H3AsO4 ===========> H^+ + AsO4^-
H3AsO4 ===========> 2H^+ + AsO4^2-
H3AsO4 ===========> 3H^+ + AsO4^3-
Therefore, the total charge balance is given as:
[H^+] =[OH^-] + [ AsO4^-] + 2[ AsO4^2-] + 3[ AsO4^3-].
Kindly note that the [OH^-] is from water.
In metallic bonding, the electrons A. are unable to move. B. are shared between two single atoms. C. are given to one atom by another atom. D. are in a "sea" around the protons of all the metal atoms.
Answer: I think it’s A.
Explanation:
Tell me if it’s wrong sorry, I am only in middle school level science.
how many moles of CO2 are produced from the combustion of 5.25 moles of CH3OH?
First, we write the reaction for CH3OH combustion
CH3OH+3/2O2--->CO2+2H2O
for 1 mole of methanol, we get 1 mole of CO2, therefore for 5,25 moles of methanol we will get 5,25 moles of CO2
A radioactive element having and atomic number 82 and atomic mass 214 emits a beta particle. The resulting element is:______.
Answer:
[tex]\frac{214}{83} Bi[/tex]
Explanation:
In beta emission, a neutron is converted into a proton thereby reducing the neutron:proton (N/P) ratio.
When a beta emission occurs, the mass number remains the same while the nuclear charge increases by one unit. The daughter nucleus is found one place to the right of its parent in the periodic table.
What is true of all atoms?
Answer:
Atoms are the building blocks of matter. They are the smallest particles of an element that still have the element's properties. All atoms are very small, but atoms of different elements vary in size. Three main types of particles that make up all atoms are protons, neutrons, and electrons.
Explanation:
Answer:
Atoms are the basic building blocks for life