Answer:
Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. Based on these results, Rutherford proposed the nuclear model of the atom.
Explanation:
1s 2s22p63s23p4
How many valence electrons does this atom have?
2
6
4
12
Answer:
6
Explanation:
How many valence electrons does this atom have?
answer 6
Answer:
6.
Sulphur has 6 valence electrons.
( .°. that's the electronic configuration of sulphur .)
Que. 1. Gallium has 2 naturally occuring Isotopes with mass numbers 69 & 71 respectively. What is the percentage abundance of both Isotopes if their relative atomic mass is equal to 70.59 Amu (Atomic mass Unit)
Isotopes are atoms of the same element that have different masses. The relative atomic mass (am) is a weighted average that takes into account the abundance of each isotope. We can calculate the relative atomic mass using the following expression.
[tex]am = \frac{\Sigma m_i \times ab_i}{100}[/tex]
where,
mi: mass of each isotopeabi: percent abundance of each isotopeFor Gallium,
[tex]70.59 amu = \frac{69 amu\ x + 71 amu\ y}{100}[/tex] [1]
where "x" and "y" are the unknown abundances.
We also know that the sum of both abundances must be 100%.
x + y = 100
y = 100 - x [2]
If we replace [2] in [1], we get
[tex]70.59 amu = \frac{69 amu\ x + 71 amu\ (100-x)}{100} \\7059 amu = -2 amu\ x + 7100amu \\x = 20.5[/tex]
Then, in [2]
y = 100 - x = 100 - 20.5 = 79.5
In conclusion, Ga-69 has an abundance of 20.5% and Ga-71 has an abundance of 79.5%.
You can learn more about isotopes in: https://brainly.com/question/21536220?referrer=searchResults
Are all elements atoms and are all atoms elements?
Answer:
yes
Explanation:
because is smallest element that are made up of atom
Answer: Yes
Explanation:
A 45g Aluminum spoon (specific heat 0.88J/g degree Celcius) at 24 degrees Celcius placed in 180ml(180g) of coffee at 85 degrees Celcius and the temperature of the two become equal. What is the final temperature?
Answer:
82 °C
Explanation:
Let the specific heat capacity of the coffee be that of water which is 4.2 J/g °C.
Now, at the final temperature, heat gained by Aluminum spoon ,Q equals heat lost by coffee, Q'.
Q = -Q'
Q = m₁c₁(T₂ - T₁) where m₁ = mass of aluminum spoon = 45 g, c₁ = specific heat of aluminum = 0.88 J/g °C, T₁ = initial temperature of aluminum spoon = 24 °C and T₂ = final temperature of aluminum spoon.
Q' = m₂c₂(T₂ - T₃) where m₂ = mass of coffee = 180 g, c₂ = specific heat of coffee = 4.2 J/g °C, T₃ = initial temperature of coffee = 85 °C and T₂ = final temperature of coffee.
So, Q = -Q'
m₁c₁(T₂ - T₁) = -m₂c₂(T₂ - T₃)
Making T₂ subject of the formula, we have
m₁c₁T₂ - m₁c₁T₁ = -m₂c₂T₂ + m₂c₂T₃
m₁c₁T₂ + m₂c₂T₂ = m₂c₂T₃ + m₁c₁T₁
(m₁c₁ + m₂c₂)T₂ = m₂c₂T₃ + m₁c₁T₁
T₂ = (m₂c₂T₃ + m₁c₁T₁)/(m₁c₁ + m₂c₂)
substituting the values of the variables into the equation, we have
T₂ = (180 g × 4.2 J/g °C × 85 °C + 45 g × 0.88 J/g °C × 24 °C )/(45 g × 0.88 J/g °C + 180 g × 4.2 J/g °C)
T₂ = (64260 J + 950.4 J)/(39.6 J/°C + 756 J/°C)
T₂ = 65210.4 J/795.6 J/°C
T₂ = 81.96 °C
T₂ ≅ 82 °C
17. The name of the reaction that produces esters is
A. addition.
B. anionic initiated polymerization.
C. radical initiated polymerization.
D. dehydration
Answer:
the name of reaction that produces esters is dehydration.
Which of the following represents an endothermic reaction?
Select one:
a. S(s) +O2(g) → SO2(g) ΔH = -297kJ
b. 2NO2(g) → N2(g) + 2O2(g) + 33.8kJ
c. N2(g) + 2O2(g) + 90.4kJ → 2NO2
d. N2H4(g) + O2(g) → N2(g) +2H20(g) + 627.6 kJ
B because decomposition reactions are often caused by the application of heat to break up the bonds within the molecules, which will form the molecules that made up the decomposed molecule.
WILL MARK BRAINLIEST IF CORRECT
Answer:
3 - a heterogeneous mixture
4- Sweet tea is an homogeneous mixture
Answer:
Explanation:
6. d
7. b
8. c
How many Calcium (CA) Atoms are in Calcium Oxide
The number of joules required to heat one gram of a substance one degree Celsius is _____.
endothermic
temperature
exothermic
specific heat capacity
summer school is over, and I'm feeling self-destructive. Take all of my points and have a good night. 3/3
ayo thanks mate :0000000000000000000000
Which elements on the periodic table are the least reactive? (1 point)
o the group with helium at the top
the group with hydrogen at the top
the group with carbon at the top
the group with fluorine at the top
Answer:
the group with helium at the top
Explanation:
I just took it
ASAP
What happens to a glass of pure fruit juice when water is added to it?
A - The number of moles of fruit juice increases.
B - The number of moles of fruit juice decreases.
C - The molarity of the juice increases.
D - The molarity of the juice decreases.
D. The MOLARITY of the juice DECREASES when water is added to it.
MOLARITY refers to the amount of a substance (solute) in a certain volume of solution. It is a measure of the CONCENTRATION OF A SOLUTION. In chemistry, molarity is calculated by dividing the number of moles of a solute by the volume of the solvent i.e.
MOLARITY (mol/L or M) = number of moles (n)/volume of solvent (V)
* The above equation means that the molarity of a solution is inversely proportional to its volume i.e. as molarity increases, volume decreases and vice versa.
According to this question, water is added to a glass of pure fruit juice (dilution). This means that the volume of the juice will increase. As the volume increases via addition of water, the MOLARITY DECREASES.
Learn more: https://brainly.com/question/20899596
Suggest a way that a scientist could create an even more accurate model of universe expansion
Answer:
Between galaxies, retake the measurement.
Explanation:
Among both galaxies, reiterate the measurements. Instead of utilising a balloon, a scientist might create a model that shows in which everything really is and how cosmos is expanding rather than expanding. By inflating up the atmosphere to 1/2, 3/4, and full size, continue the operation.
Which of the following pairs of elements will form ionic bonds with each
other?
A. Silver (Ag) and silver (Ag)
B. Lithium (Li) and iodine (1)
C. Bromine (Br) and bromine (Br)
D. Carbon (C) and chlorine (CI)
Answer:
B. Lithium (Li) and iodine (1)
Explanation:
Ionic bond is a type of chemical bond that is formed between a metallic element and a non metallic element. The positive charge of the metallic ion is attracted to the negative charge of the non metallic ion to form an ionic bond.
According to the options given in this question, lithium and iodine will form an IONIC bond because lithium is a cation (+ve ion) while iodine is an anion (-ve).
plz search rhe chemistry project on any topic..
IF NOT THEN SORRY :)
What would you need to do to calculate the molality of 10 g of NaCl in 2 kg of
water?
A. Convert the 2 kg of water to liters of water.
O B. Convert the 10 g of NaCl to moles of NaCl.
C. Convert the 2 kg of water to moles of water.
O D. Convert the 10 g of NaCl to kg of NaCl.
Answer:
O B. Convert the 10 g of NaCl to moles of NaCl.
Explanation:
The formula for finding the molality is m=moles of solute/kg of solvent. The solute for this question is NaCl and the solvent is water.
(10g NaCl)(1 mol NaCl/58.44g NaCl)=0.1711 mol NaCl
58.44 is the molar mass of NaCl
m=0.1711 mol NaCl/2 kg H2O
m=0.085557837
What is a weak acid?
A. An acid that does not have a conjugate base
B. An acid that does not dissolve completely
C. An acid that has been diluted with water
D. An acid that has a very low pH value
Answer:
B
Explanation:
strong acids ionize completely in water
Answer:
An acid that does not dissolve completely
Explanation:
26. Calculate the mass of hydrogen formed when 25 grams of aluminum reacts with excess hydrochloride acid. 2AI + 6HCl →l Al2Cl6 + 3H2
Answer:
2.76 gram
Explanation:
2AI + 6HCl → 2AlCl3 + 3H2
get the mol of aluminum => n = m / M = 25 / 27 = 0.925 (mol)get the ratio mol of Hydro => nH2 = 0.925 * 3 / 2 = 1.38 (mol)get weight of hydro mH2 = n x M = 1.38 x 2 = 2.76 (gram)Answer
Al +2 HCl - AlCl2 + H2
PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ HELP ME......
Answer:
a) clockwise
b) clockwise and
c) anticlockwise
balance this equation
PB3 O4 + H2 → PB + H2O
Answer:
Pb3O4 + 4H2 → 3Pb + 4H2O
Explanation:
Pb3O4
Tritium - H2
Molar Mass of H2 Bond Polarity H-3 Hydrogen-3 3H T
Products
Lead - Pb
Molar Mass of Pb Plumbum Element 82 Bulk Lead
Water - H2O
Molar Mass of H2O Oxidation Numbers of H2O Dihydrogen Monoxide Dihydridooxygen Hoh Hydrogen Hydroxide Dihydrogen Oxide Oxidane Hydrogen Oxide Pure Water
When a leaf of fresh sage or mint is rubbed ,the fragrance is
immediately obvious. Write a theoretical explanation for this observation
Answer: Volatile compounds present in the fresh sage leaf or mint leaf evaporate on rubbing.
Explanation:
When fresh sage or mint is rubbed on the skin or any other surface the volatile chemicals associated with the integral structure of the plant part get evaporated in the surrounding air and the vapors can be detected by the olfactory receptors present in the nose. These receptors take the smell or fragrance stimulus and generate impulses or signals which goes to brain and brain interprets the smell or fragrance.
an atom contains positive protons and negative electrons. Why atom is electrically neutral.
Answer:
atom is electrically neutral because
the no.of protons is equal to no.of
electrons.
Therefore the negative charge and
positive charge cancels out.
Need help :)….please
Answer:
i think B is correct
Explanation:
10. What do you understand by a balanced chemical equation? Explain with the an example.
Explain the bonding that occurs between sodium and chlorine. Specifically, what kind of bonding takes
place, what’s the name of the resulting compound, and what properties would you expect this compound to
have with respect to water?
Answer:
About bonding
Explanation:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bond.
Answer:
An ionic bond occurs between sodium and chlorine where sodium has one electron while chlorine has seven electrons. The electron from sodium is lost and transferred to a chlorine atom which results in a sodium ion with a charge of one+ and a chloride ion with a charge of one-. These oppositely charged ions attract each other making a balanced charge to make a compound that is electrically neutral.. Sodium cation (Na+) and chlorine anion (Cl-) are attracted to each another to form sodium chloride (table salt). When dissolved in water, the sodium and chloride ions are strongly attracted to the polar water molecules because of ion-dipole interactions.
Explanation:
What happens when acetylene reacts with silver powder?
why do the aquatic plants not break down by water current?
What are three ways that plastic pollution is harmful on land
Answer:
Plastic pollution are harmful on land because;
It can make human felt sick which is not healthy for us.How did elements get to earth?
the universe formed through the big bang explosion, all of the elements on Earth have been cooked for billions of years in stars and then released in the universe through super- nova explosions.
9. Which is true of a radioisotope that is used to date rock formations?
Answer:
Radiometric dating or radioactive date is the method that uses radioisotope to date the formation of a rock. The age of the rocks will be determined.
Explanation:
Radioactive deterioration is a natural process and results from the unstable atomic core, which releases bits and parts.
These radioactive particles are released as (there are many types). This decline process results in a more equilibrated nucleus, which makes the atom stable when the number of protons and neutrons balances.
This radioactivity is suitable for dating, as a radioactive "parent" item is constantly decaying into a stable "daughter" element.
A single mineral grain or a whole rock may be dated. There are techniques by which the sample is excited in a nuclear reactor and then measured with a mass spectrometer. The isotope (such as in the argon-argon scheme).
Others put mineral grains under a special microscope, fir in the grains with an ionising laser beam that releases the mineral and the isotopes.
The isotopes are measured by a mass spectrometer inside the same machine (an example of this is SIMS analysis).
