Answer:
14.52%
Explanation:
The percentage by mass (WW%) is calculated by using the formula:
Mass of solute/mass of solution ×
100
The solute (Al) is 22.5g while the solvent (Al2O3) is 155g
Hence, percent by mass is:
22.5/155 × 100
= 0.1452 × 100
= 14.52%
what is the half life of the element in the picture
HELP BRAINLIEST
Answer:
6 days
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 100 mg
Amount remaining (N) = 6. 25 mg
Time (t) = 24 days
Half life (t½) =?
Next, we shall determine the decay constant. This can be obtained as follow:
Original amount (N₀) = 100 mg
Amount remaining (N) = 6. 25 mg
Time (t) = 24 days
Decay constant (K) =?
Log (N₀/N) = kt / 2.303
Log (100/6.25) = k × 24 / 2.303
Log 16 = k × 24 / 2.303
1.2041 = k × 24 / 2.303
Cross multiply
k × 24 = 1.2041 × 2.303
Divide both side by 24
K = (1.2041 × 2.303) / 24
K = 0.1155 /day
Finally, we shall determine the half-life of the isotope as follow:
Decay constant (K) = 0.1155 /day
Half life (t½) =?
t½ = 0.693 / K
t½ = 0.693 / 0.1155
t½ = 6 days
Therefore, the half-life of the isotope is 6 days
{b}
In experiment B. the iron filings weighed 2.0g at the beginning of the experiment
and the iron sulphide produced weighed 2.8g.
Explain this increase in mass.
Explanation:
The increase in mass is because the iron fillings have combined with a sulfide to produce iron sulfide and so the mass will increase.
In such a reaction like this, the mass of the reactants must be conserved. By so doing, the mass of reactants and products must be the same.
When two substances combine together, their masses added up to that of the individual masses. This helps to conserve the mass.
i’ll mark brainliest please
Based on the equation below, which of the following statements best describes what should be observed as the reaction takes place?
Zn(s) + 2HCl(aq) = ZnCl2(aq) + H2(g)
Select one or more:
a. Chlorine forming a solid precipitate
b. Bubbles forming from hydrogen gas production
c. Solid zinc dissolving
d. Bubbles forming from chlorine gas production
Can you help me please
Answer: B
Explanation:
B
How many sig figs in each?
-27.43
-1.90
-101
a
Which property of a gas affects the rate at which it spreads throughout
laboratory?
Answer:
Diffusion is faster at higher temperatures because the gas molecules have greater kinetic energy. Effusion refers to the movement of gas particles through a small hole. Graham's Law states that the effusion rate of a gas is inversely proportional to the square root of the mass of its particles
Which of the following occurs in an ionic bond?
А)
Oppositely charged ions attract.
B)
Two atoms share two electrons.
C)
Two atoms share more than two electrons.
D)
Like-charged ions attract.
Answer:
The answer should be Oppositely charged ions attract. So A.
Explanation:
Be sure to use two (2) sources of information (one source can be your book). In your response, you MUST state your source. Your response should be between 100 and 150 words.
Answer:
^=E9>*t
Explanation:
which element is found in laundry products?
boron or sulfur
The diagram shows the electron arrangement in a molecule of ammonia, showing only outer
shell electrons.
I
H
(i) State the type of bonding in ammonia.
1
6
The diagram shows 5 eletctron in the outermost shell of Nitrogen atom out of which 3 electrons are involved in the bond formation with 3 Hydrogen atoms.
The type of bond in ammonia is Covalent.
What is covalent bond ?Covalent bond is the bond formed by mutual Sharing of electrons by both the atoms taking part in the bond formation.
Nitrogen has 5 valence electrons of which only 3 are shares with the 3 atoms of hydrogen (one electron shares with one atom of hydrogen)
Hence, type of bond in ammonia is covalent.
Learn more about covalent bond here ;
https://brainly.com/question/19382448
#SPJ1
Q8: If you blow up a balloon, and then release it, the balloon will fly away. This is an example of
Which of Newton’s law is it first second or third
Answer:
it it the first law
Explanation:
Answer:it is an example of Newton’s 3rd law
Explanation:the balloon had a reaction
If a mineral has a metallic shine and scratches, which of its properties are being measured? Choose the two correct answers.
Metals have shiny surface by which they reflect light. The two properties which can be measured from the metallic shine and scratches in a metal are its luster and hardness.
What are metals?Metals are electropositive elements conducts thermally and electrically. Almost all metals shows a shining property when they reflect light and it is called metallic luster.
Hardness of a metal can be a measure how much the metals resists scratches. Very hard metals do not form powders on scratching. Less hard metals may effect by scratches.
More hard and shining metals have various applications such as in construction fields, optoelectronic devices, thermal coatings and corrosion resistant products.
Hence, option a and b, hardness and luster can be measured from the scratches and metallic shining respectively.
To know more about metals, refer the link below:
https://brainly.com/question/18153051
#SPJ2
Your question is incomplete, but most probably your full question was:
If a mineral has a metallic shine and scratches, which of its properties are being measured?
choose the two correct answers.
a. luster
b. hardness
c. magnetism
d. cleavage
If an unknown solution has a pH of 9, what is that solution classified as?
A.Solid
B.Neutral
C.acid
D.Base
Answer:
option A is the ans i think so
If an unknown solution has pH of 9 the solution is classified as a base as it has larger concentration of hydroxyl ions.
What is base?
According to the Arrhenius concept, base is defined as a substance which yields hydroxyl ions on dissociation.These ions react with the hydrogen ions of acids to produce salt in an acid-base reaction.
Bases have a pH higher than seven as they yield hydroxyl ions on dissociation.They are soapy in touch and have a bitter taste.According to the Lowry-Bronsted concept, base is defined as a substance which accepts protons .Base react violently with acids to produce salts .Aqueous solutions of bases can be used to conduct electricity .They can also be used as indicators in acid-base titrations.
They are used in the manufacture of soaps,paper, bleaching powder.Calcium hydroxide ,a base is used to clean sulfur dioxide gas while magnesium hydroxide can be used as an antacid to cure acidity.
Learn more about base,here:
https://brainly.com/question/12445440
#SPJ2
Calculate the frequency of a wave that is 4.3 x 10^-11 m the speed of light 5 points
is 3x10^8 m/s *
1 Add file
PLEASE HELP
GIVING AWAY 70 PTS AND BRAINLIEST ANSWER QUICK!
Which of the following techniques can be used to separate a heterogeneous mixture into its component parts? A Sort by colour B Separation by density C Apply heat D Apply pressure
Answer:
i think it might be separation by density
Explanation:
Answer:
B: Sort by density
Btw im not copying the person above me. I am 98% Sure its density
What does a particular point on a line of a phase diagram represent ?
Answer:
the line represents the condition where pressure and heat have the same effects.
Answer: C) The melting point of a substance at a specific pressure.
Someone please help will mark as brainliest
Answer:
solution:-a homogenous mixture of two or more substances in relative amounts that can be varied continuously up to what is called the limit of solubility.
solute:-is a substance, usually a solid, that is dissolved in a solution, which is usually a liquid.
solvent:-substance, ordinarily a liquid, in which other materials dissolve to form a solution.
polar molecule:-is a molecule in which one end of the molecule is slightly positive, while the other end is slightly negative.
Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.
concentration refers to the amount of a substance in a defined space.
Explanation:
Which evidence is an indication that a chemical reaction has occurred?
a.melting substance
b.boiling substance
c.frezzign of substance
d.formation of a gas
Answer is D formation of gas.
Explanation: I hope that helped/have a great day.
Birthday candles are lit on your cake
Physical change or chemical change?
Answer:
Physical change
Explanation:
while the wax is melting its still wax no chemical change
hope this helps :3
if it did pls mark brainliest
All atoms of the same element:
have the same number of electrons
have the same number of protons
have the same number of atoms
have the same number of neutrons
Answer:
have the same number of protons
Explanation:
Atoms of the same element will always have the same number of protons.
Protons are the positively charged particles in an atom which are located in the nucleus.
To recognize an atom, the number of protons is used. The number of protons is the atomic number.On the periodic table, atoms are arranged based on the number of protons.PLS I NEED HELP!! Lucia wants to arrange the four states of matter from lowest kinetic energy to highest kinetic energy. How should she arrange them?
A. liquid, solid, plasma, gas
B. liquid, solid, gas, plasma
C.solid, liquid, plasma, gas
D. solid, liquid, gas, plasma
Answer:
Basically, the more hot the state is, the more kinetic energy it will have. This means that answer D. would be right, as it goes from coldest to hottest states!
Answer:
The answer is D. solid, liquid, gas, plasma
Explanation:
When you connect your evidence to your claim you are using your
1. brain
2.reasoning
3. test
Answer:
2. reasoning
Explanation:
PLS GIVE BRAINLIEST
Explain the difference between Carbon-9 and Carbon-14. Which version Carbon do you believe is the most stable? Why? What information could help you confirm your prediction?
correct form of question is
Explain the difference between Carbon-12 and Carbon-14. Which version Carbon do you believe is the most stable? Why? What information could help you confirm your prediction?
Answer:
Carbon has three isotopes those are carbon- 12 , carbon - 13 , carbon-14 among these only C-12 and C-13 are stable while C-14 is radioactive.
C-12 has 6 protons and 6 neutrons , C-14 has 6 protons and 8 neutrons. Atoms with equal number of protons and electrons are generally stable however C-12 and C-14 have 6 electrons but due to excess neutrons present in C-14 makes it undergo radioactivity therefore it is unstable.
what are things that we can eat or drink to make our stomach less acidic?
Answer:
Opt for foods low in sugar and fat and high in fiber.
Explanation:
Any noncitrus fruits, oatmeal, leafy green vegetables, ginger is excellent for heartburn and stomachaches.
What is the average isotope mass?
Answer:
the atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope
Explanation:
Average atomic mass = f1M1 + f2M2 + … + fnMn where f is the fraction representing the natural abundance of the isotope and M is the mass number (weight) of the isotope. The average atomic mass of an element can be found on the periodic table, typically under the elemental symbol.
Answer:
he atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.
how does sodium become an ion
Answer:
Sodium is an alkali metal so it needs to lose an electron to fill it's outer shell.
That is an ion. When an element loses or gains an electron but in this case, sodium needs to lose an electron.
A boat sails into a bay and drops anchor. Several hours later, it is surrounded by mud. What
happened?
Answer:
the flow of the water pushed the mud around the anchor
Explanation:
The information regarding the mud should be explained below:
The following information should be considered:
In the case when it should be surronded by mud so there is low tide arise.it is occur at the time when the water retreats to its lowest level, moving away from the shore.Learn more: https://brainly.com/question/5763151?referrer=searchResults
Which of the following is not an example of biased language?
a.
“You are too short to reach that.”
b.
“Are you deaf?”
c.
“Move along, grandpa!”
d.
“I think I’ve been gypped.”
Answer:
I think it is D.
Explanation:
Answer:
b
Explanation:
How many moles are contained in 5.0 g of SO2:
Hey there!
Molar mass SO₂ = 64.066 g/mol
Therefore:
1 mole SO₂ -------------------- 64.066 g
(moles SO₂ ) ??---------------- 5.0 g
( moles SO₂) = 5.0 * 1 / 64.066
(moles SO₂) = 5.0 / 64.066
moles = 0.0780 moles of SO₂
Hope this helps!
