Answer:
a) 29.0 years
b) 0.89 g
Explanation:
Using the formula
t1/2= t×ln2/ln(No/Nt)
Where
Nt= mass of radioactive isotope at time= t =0.953g
No= initial mass of radioactive isotope present= 1.000g
t= time taken for N mass of radioactive isotope to remain = 2 years
t1/2 = half-life of radioactive isotope= ???
Substituting the values
t1/2= 2 × ln2/ln(1.000/0.953)
t1/2= 2× 0.693/0.048
t1/2= 29 hours
b)
N= No(1/2)^t/t1/2
Where t= 5 years
N= 1.000(1/2)^5/29
N= 1.000(1/2)^0.17
N= 0.89g
what is the mass of 7.525 x10^24 particles of sulfur difluoride SF2?
Answer:
Mass will be equal to 874.56 gram
Explanation:
Molar mass of sulfur = 32 u
Molar mass of Florine = 19 u
Therefore molar mass of [tex]SF_2[/tex] [tex]=32+2\times 19=70u[/tex]
So mass of [tex]6.023\times 10^{23}[/tex] particle is 70 gram
Therefore mass of 1 particle
[tex]=\frac{70}{6.023\times 10^{23}}=11.62\times 10^{-23}g[/tex]
Therefore mass of [tex]7.525\times 10^{24}[/tex] particle is
[tex]7.525\times 10^{24}\times 11.62\times 10^{-23}=874.56gram[/tex]
(Multiple Choice, 30 pts)
A student wants to determine whether an unknown solid is an ionic compound. He puts some in water and finds that it does not dissolve. He says that this proves the solid is ionic. Which best evaluates the student's reasoning?
A. He is incorrect, because water can dissolve ionic solids.
B. The test proves nothing, because water dissolves all solids.
C. He is correct, because polar liquids cannot dissolve ionic solids.
D. The test proves nothing, because it only shows that the solid is a compound.
(I know water is polar, so I think its a?)
The student cannot prove that if the compound is ionic or covalent because not all ionic compounds dissolves in water. Some ionic compounds have higher lattice energy results in lower solubility. Thus, option D could be correct.
What are ionic compounds?Ionic compounds are formed between metals and non metals. Metals are electron rich and they easily donate electrons to the non-metals. Non-metals are generally electronegative and they easily gains electrons from the metals.
Donating electrons make metals acquire positive charge and the non-metals acquire a negative charge. This charge separation make the compound possess a permanent dipole moment. Which make them easily soluble in water by ion-dipole interaction.
However, some ionic compounds have very strong ionic bonds and their binding energy will be greater so that cannot be easily dissolved in water. For example, AgCl. Therefore, we cannot predict weather the compound is ionic or not by simply noting it solubility in water.
To find more on ionic compounds, refer here:
https://brainly.com/question/9167977
#SPJ3
In the following reaction 6.13g of water (H,O) is produced the theoretical
yield of water (H,O) is 8.17g, what is the percent yield of water?*
C3H8+ 5 O2 → 3 CO2 + 4 H2O
85.0%
72.0%
75.0%
0 67.0%
help me name these molecules please
Answer:
1. carboxylic acid
2. ether
3. ester
4. aldehyde
5. ketone
6. amine
7. alcohol
Explanation:
Know the functional groups. If you would like to learn them, let me know.
- Hope that helps! Please let me know if you need further explanation.
HELP CHEM ASAP!!!!!!
Answer:
0.132
Explanation:
is the only part i know
Ca(OH)2
Name this compound according to IUPAC nomenclature.
A) calcium hydroxide
B) calcum oxide hydride
C) calcium (II) hydroxide
D) calcium (II) oxide hydride
A sample of carbon dioxide occupies a volume of 1.50L at 165KPå pressure. What pressure would the gas exert if the volume was increased to
2.5L?
a.0.023 kPa
b. 275 kPa
c. 99 L
d. 99 kPa
Answer:
B. 275 kPa
Explanation:
Since we need to find the greater value, because 1.50<2.5, then the only greater value would be 275 kPa.
How is the atmospheric oxygen that is taken in by living things for respiration replaced?
A) After living things use oxygen for respiration, they exhale the oxygen back to the atmosphere.
B) Photosynthesis uses the carbon dioxide that is exhaled by living things to make oxygen.
C) Weathering releases oxygen that is locked in rocks due to sedimentation.
D) Oxygen that is dissolved in water such as oceans is released.
Answer:
B.) Photosynthesis uses the carbon dioxide that is exhaled by living things to make oxygen.
Explanation:
During light-dependent reactions, carbon dioxide is converted to glucose.
Group of answer choices
True
False
Answer:The light-independent reactions use the ATP and NADPH from the light-dependent reactions to reduce carbon dioxide and convert the energy to the chemical bond energy in carbohydrates such as glucose.
Explanation:step-by-step
Answer:
FALSE
Explanation:
I just took the test and put true and it was wrong so it's false. Hope this helps and please mark brainliest!
The map shows the main streams and the the rivers near City A and City B, as well as the nearby factories and farmland, The arrows in
the diagram show the direction of the water flow. City A gets its water from the sunset River and City B gets its water from the Moth Lake. A liquid herbicide was applied to a farmland. What is the greatest risk of using the herbicide?
Select One:
It will pollute the water source for the city A
It will pollute the air for the City B
It will pollute the water source of city B
It will pollute the air for the city A
Answer:
c
Explanation:
the map shows water near the factories go into moth lake so all of the waist will end up there
How do American cities now protect their water resources
Answer:
They can use man made materials or they can also have designed areas that people can’t go into
Explanation:
A sample of water is heated from 10.0 degrees Celcius to 15.0 degrees Celcius by the addition of 125 Joules of heat. What is the mass of the water?
Answer:
125 = 5*4.186*m
m = 125 / 5*4.186 = 5.97g of water.
Explanation:
The water is increased by 5 degrees. This means that for every gram of water, it takes 5*4.186 J to increase the temperature by 5 degrees, aka 5*4.186 J/g
hope this help:)
Cuando se queman combustibles que tienen algún compuesto de azufre se produce dióxido de azufre (SO2), un gas irritante que puede provocar lluvia ácida. En el análisis del aire de una ciudad se ha encontrado una concentración de SO2 de 14 mg/m^3 ¿Qué cantidad de SO2 habrá en 1 L de aire?
Answer:
See answer below
Explanation:
I have to answer this question in english because is the rule here. I hope you can understand this.
Now, in order to answer this, is really easy. We already have the quantity of SO₂ in the air of a city. This concentration is 14 mg/m³, so we want to know the quantity in 1 L. This quantity can be expressed in mass.
If concentration according to the units is: mg/m³ This means that we have units of mass and volume. So, in order to know the quantity of SO₂ in mass, we need to convert the units of volume m³ to liter.
1 m³ is covered in 1000 L, therefore:
14 mg/m³ * 1 m³/1000 L = 0.014 mg/L
Then, the mass will be:
m = 0.014 mg/L * 1 L
m = 0.014 mg of SO₂
This is the quantity of SO₂ in 1 L.
PLS HELP
In the balanced equation:
H3PO4(aq) + NH3(aq) ↔ X(aq) + NH4+(aq)
The particle represented by X(aq) is
A) H2PO4–(aq)
B) HPO42–(aq)
C) PO43–(aq)
D) H3PO4(aq)
Answer:
The particle represented by X(aq) is A) H₂PO₄⁻(aq)
Explanation:
According to the Brønsted-Lowry Theory, a base is a substance capable of accepting protons (H⁺) in solution. Conversely, a substance acts as an acid if it acts as a proton donor.
A proton transfer then occurs, requiring the presence of a proton donor (an acid) and a base that accepts them.
When an acid gives up a proton, it becomes an anion, generating a conjugate base. That is, a conjugate base is an ion or molecule resulting from the acid that loses the proton. Conversely, a conjugated acid is an ion or molecule resulting from the base that the proton gains.
In this NH₃ / NH₄⁺ pair that NH₄⁺ is the conjugate acid of the NH₃ base, the latter acting as a base since it accepts a proton. H₃PO₄ then acts as an acid, yielding a proton and generating the conjugate base H₂PO₄⁻.
So, the particle represented by X(aq) is A) H₂PO₄⁻(aq)
in a titration 20.0 mL of 0.150 M NaOH(aq) Solution exactly neutralize is 24.0 mL of an HCl solution what is the concentration of the HCl solution
Answer:
0.125
Explanation:
i took a test and got it right choosing this answer hopes this help
Temperature and volume are
_____ related, which means as temperature______
the volume decreases.
Answer:
They are directly related.
Temp decrease then volume decrease
Temp increase then volume increase
The balloon in this image was rubbed with a piece of wool material. Now, it is negatively charged. What force allows the charged balloon to "pick up" the small pieces of paper off of the table?
The negatively charged balloon is attracted to negative static charges in the paper..
The negatively charged balloon is attracted to the north pole of the paper pieces.
The negatively charged balloon is attracted to the south pole of the paper pieces.
The negatively charged balloon is attracted to the positive static charges in the paper.
What is the best explanation of electric current in a wire?
Electrons build up in the wire and create a charge.
Electrons flow because of electrical attraction and repulsion.
Protons are pushed along by electric forces.
Atoms move because of heat.
Why does the light bulb in a circuit turn on when you close the switch?
The switch absorbs the electrical energy.
The switch changes the direction of the flow of electrons.
Closing the switch completes the circuit, making it a closed circuit.
The switch changes the circuit from series to parallel.
Earth is dipolar, like a bar magnet.
What does this mean about its magnetic poles?
There is only a magnetic south pole.
There is only a magnetic north pole.
There are both magnetic north and south poles.
There are two magnetic north poles.
Which arrangement described below would result in magnetic poles that attract one another?
North Pole + South Pole
South Pole + West Pole
East Pole + North Pole
North Pole + North Pole
Why is an electromagnet a temporary magnet?
An electromagnet only attracts other permanent magnets.
An electromagnet becomes a magnet when a current flows through the wire. An electromagnet no longer acts as a magnet when the current flow stops.
An electromagnet cannot be turned on and off.
An electromagnet is a magnet when no current flows through the wire. The electromagnet no longer acts as a magnet when current flows through the wire.
What set of materials listed below could be used to create a complete electromagnet?
wires and battery
iron nail and battery
iron nail, magnet, and wire
battery, iron nail, copper wire
Where is a bar magnet's magnetic field the strongest?
red part of the magnet
longest part of the magnet
magnetic poles (N + S)
center of the magnet
A(n) ___________ is represented in the diagram it converts electrical energy into mechanical motion.
generator
electromagnet
parallel circuit
motor
Answer:
I actually have no idea
Explanation:
Sorry my man
Answer:
Explanation:
generator
Ms. Clark is teaching her class about how plants make food for themselves. On the board, she has written this: __________ + air + water = food for plants
Answer:
sunlight
Explanation:
How are renewable fuels different from fossil fuels
Answer:
Renewable energy
Explanation:
on the other hand, typically emits less CO2 than fossil fuels. In fact, renewables like solar and wind power—apart from construction and maintenance—don't emit any CO2 at all. With renewable energy, you can breathe easier, stay cooler, and create a more comfortable world for generations to come.
Answer:
renewable energy comes from natural resources that can be replenished or replaced during an average human lifetime ; eg, Hydro, solar, wind etc.
fossil fuels can take thousands or even millions of years to naturally replenish; eg, natural gas, coal, oil.
I’ll give Brainliest to the first answer
The amount of elements on the reactants side of an isolated equation are ___________ the amount of __________ that are formed on the ________ side. *
A)close to, ice crystals, cold
B)less than, properties, chemical
C)equal to, elements, products
D)similar, molecules, present
E)more than, elements, products
Answer:
C. equal to, elements, products
Explanation:
I took a quiz and it said this was right
Which has the highest rate of effusion oxygen or hydrogen
Answer:
Hydrogen has the highest rate of effusion
Which phrase provides the best definition of mass movement?
the movement of material caused by erosion
the slow flow of a glacier as it moves through the valley of a mountain
the movement of large amounts of soil and rock debris down a slope
the fast movement of a boulder rolling down a slope
Answer:
the movement of large amounts of soil and rock debris down a slope
Explanation:
yeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeetyeet
Does anyone know how to solve this
Answer:
Beta
Explanation:
Beta has signal 0 above and -1 under
Sulfuric acid (H2SO4) has a molar mass of 98.1 g/mol. How many oxygen atoms are found in 75.0 g of H2SO4? A. 1.15 × 10^23 B. 1.84 × 10^24 C. 4.61 × 10^23 D. 7.87 × 10^23
Answer:
B
Explanation:
first find the no. Of moles of H2SO4
= 75/98.1
= 0.7645
Next step
In on mole of H2SO4 the no.of oxygen atom is 4.
1 H2SO4 : 4 O
0.7645 : x x= 0.7645x4= 3.0581
next multiply avogadros constant
3.0581 x 6.022× 10^23 =1.84x10^24
Mass present in 1 gram of mole substance is called molar mass. Molar mass is calculated by: dividing the mass of the compound in grams by the number of moles present in the substances.
The correct answer is:
option B. 1.84 × 10²⁴
Given,
The mass of sulfuric acid =75.0 gThe molar mass of sulfuric acid = 98.1 g/mol
1.The moles of sulfuric acid can be calculated by
M = m ÷ n
where M is molar mass, m is mass and n moles.
moles of sulfuric acid = mass ÷ molar mass
= 75 g ÷ 98.1 g/mol
=0.7645 moles
Hence moles of sulfuric acid present is 0.7645 moles.
2. 1 mole of sulfuric acid = 4 oxygen atoms.
Then, 0.7645 moles of sulfuric will contain: 0.7645 × 4 = 3.0581 atoms of oxygen
3. Oxygen atoms present in 75.0 g of H₂SO₄ will be calculated by multiplying it with Avogadro's constant:
= 3.0581 x 6.022× 10²³
= 1.84x10²⁴
Therefore, 1.84 × 10²⁴ oxygen atoms will be found in 75.0 g of H₂SO₄.
To learn more about moles follow the given link:
https://brainly.com/question/20486415
what is the compound of libr
Answer:
Lithium Bromide
Explanation:
Answer:
El bromuro de litio es un compuesto químico de litio y bromo. Su carácter higroscópico extremo hace que LiBr sea útil como desecante en ciertos sistemas de aire acondicionado.
Explanation:
How many moles of NaCl are contained in 100.0ml of a 0.20m solution
Which of the following is stored in the skeletal system?
A. potassium
B. calcium
phosphorous
D. sodium
Answer:
b calcium
Explanation:
Help Chem asap!!!!! Brainslist
Answer:
OH-
Explanation:
Question 2 options: The Galápagos tortoises are native to seven of the Galápagos Islands, a volcanic archipelago about 620 miles west of the Ecuadorian mainland. With lifespans in the wild of over ____________years, it is one of the longest-lived vertebrates. A captive individual lived at least ______________years!
Answers:
in the wild of over 100 years,...
A captive individual lived at least 255 years!
Explanation:
The giant Galapagos tortoises (Chelonoidis nigra) are famous because this species was observed by Darwin during his travel. This species is native from the Galapagos Islands and currently is in danger of extinction. Galapagos tortoises are recognized as one of the longest vertebrates. In this regard, it is worthy to note that a giant tortoise named Harriet lived 255 years, this specimen was in the Australian Zoo.
The ___________________ is an early theory which states that our solar system was formed by the gravitational collapse of a massive giant cloud.
A) Nebular Theory
B) Capture Theory
C) Proto-planet Theory
D) Schmidt-Lyttleton accretion theory
Answer: A) Nebular Theory
Explanation:
Answer:
A)
Explanation:
