Answer:
Radioactive isotopes have many useful applications. In medicine, for example, cobalt-60 is extensively employed as a radiation source to arrest the development of cancer. Other radioactive isotopes are used as tracers for diagnostic purposes as well as in research on metabolic processes.
Explanation:
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what is physical and chemical change ?
Answer:
Physical change is there is a difference in appearance, smell, etc.
Chemical change is there is change in the composition or the rearrangement of the atoms of one or more substances.
calculate the mass of onygen gas whose
volume is 320mL at 17 degree celsius and 2 atm Pressure
Answer:
The mass of oxygen gas is 0.96 g.
Explanation:
Given data:
Mass of oxygen gas = ?
Volume of as = 320 mL (320mL × 1L /1000 mL = 0.32 L)
Temperature of gas = 17 °C
Pressure of gas = 2 atm
Solution:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
17+273 = 290 K
Now we will put the values in formula.
2 atm × 0.32 L = n × 0.0821 atm.L/ mol.K × 290 K
0.64 atm.L = n × 23.81 atm.L/ mol.
n = 0.64 atm.L / 23.81 atm.L/ mol.
n = 0.03 mol
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 0.03 mol × 32 g/mol
Mass = 0.96 g
The mass of oxygen gas is 0.96 g.
The mass of oxygen will be "0.96 g".
Given:
Volume,
V = 320 mLor,
= 0.32 L
Temperature,
T = 17°Cor,
= 290 K
Pressure,
P = 2 atmGeneral gas constant,
R = 0.821 atm.L/mol.KAs we know the formula,
→ [tex]PV = nRT[/tex]
By substituting the values, we get
[tex]2\times 0.32=n\times 0.0821\times 290[/tex]
[tex]0.64=n\times 23.81[/tex]
[tex]n = \frac{0.64}{23.81}[/tex]
[tex]= 0.03 \ mol[/tex]
hence,
→ Mass of oxygen = [tex]Number \ of \ moles\times Molar \ mass[/tex]
= [tex]0.03\times 32[/tex]
= [tex]0.96 \ g[/tex]
Thus the above answer is right.
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https://brainly.com/question/14049502
There are many types of forces. Which statement best compares an electrical force to gravitational force?
A. Electrical forces hold small objects near eachother and gravitational forces hold large objects near each other.
B. Electrical forces depends on the type of charge and gravitational forces depend on the mass of the objects and how far apart they are.
C. Electrical forces are attractions between similar types of charges and gravitational forces are attractions between similar size of objects.
D. Electrical forces require that the objects are in contact with eachother and gravitational forces require the objects are far from each other.
which ion has the smallest radius
how should i read chemistry ?
Answer:
CHEMIcal hiSToRY
Explanation:
write down the group numbers for carbon,oxygen,nitrogen and sulphur
Answer:
Carbon - 14
Oxygen - 16
Nitrogen - 15
Sulphur - 16
Explanation:
The question above is related to the "Periodic Table of Elements" which shows the proper arrangement of elements in a table. Every element falls on a group/family within the table. Each group has its own number, and the table has a total of 18 groups (from left to right). They are classified according to similarities in their characteristics. For example, group 1 is composed of alkali metals while group 2 is composed of alkali earth metals.
What is the mass of an unknown object that has a volume of 20 mL and density of 3.5 g/mL?
Answer:
70
Explanation:
density=mass/volume
therefore mass = density*volume
20*3.5=70
When the temperature goes up, the volume will also go up
What is the possible reason?
Mention one real-world example?
Answer:
Yes it will
An example is ice, when it melts the volume goes up which means it occupies much more space
Plz help getting timed
Answer:
I think the first one is Active Transport.
Explanation:
The second one is passive transport
3. If Dr. Birdley is packing a if Dr.Birdley is packing a snowball, which of
the following properties is likely to increase?
a) mass
b) volume
c) density
d) weight
Answer:
c. density
hope this helps :)
Explanation:
How many moles of Magnesium are present in 0.478 g of the element?
(Atomic mass: Mg-24 u)
Answer:
0.0199moles
Explanation:
The number of miles of a substance can be calculated using the formula:
Number of moles (n) = Mass (M) / Molar mass (MM)
In this question, the mass of Magnesium element (Mg) = 0.478 g while the atomic mass is 24
Therefore, number of moles of Magnesium is:
Moles = 0.478/24
Moles = 0.01992
Hence, 0.0199 moles of Magnesium are contained in 0.478 g of the element.
How do scientist determine the ages of fossils
Answer:
Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages. Absolute dating is used to determine a precise age of a fossil by using radiometric dating to measure the decay of isotopes, either within the fossil or more often the rocks associated with it.
How many ATOMS of sulfur are present in 3.07 grams of sulfur hexafluoride ?
Sulfur tetra flouride formula is SF4 so there are 3.07 moles of sulfur ATOMS in there.
You are feeling ill, you go to the doctor, explain how he would use the scientific method to determine what is wrong with you
The doctor would form a hypothesis based on your symptoms. If you have a cough for instance, then s/he could hypothesize that you have a cold or flu. From that hypothesis, they would gather data in the form of measuring your vitals and so on. Using that data, they would be able to confirm the hypothesis, or reject it in form of some alternative.
In the early 1900's many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford completed an experiment that changed the concept of an atom. His discovery led to the understanding that an atom. His discovery led to the understanding that an atom consists of mostly empty space with
The question is incomplete; the complete question is;
In the early 1900s many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford completed an experiment that changed the concept of an atom. His discovery led to the understanding that an atom consists mostly of empty with space with-
Protons orbiting a dense nucleus made of electrons and neutrons
Electrons orbiting a dense nucleus made of protons and neutrons
Neutrons and protons orbiting a cloud of electrons
Electrons and protons orbiting a cloud of neutrons
Answer:
Electrons orbiting a dense nucleus made of protons and neutrons
Explanation:
Rutherford established the nuclear theory of the atom by his famous experiment. In his experiment, alpha particles were used to bombard a thin gold foil and the movement of the particles was observed on a moveable zinc sulphide screen.
It was discovered from the experiment that the atom was mostly made up of empty space. The electrons orbit a dense nucleus comprising of protons and neutrons.
How do you call when a substance goes from a solid to a liquid?
Answer:
Melting point as a chemistry concept
The solid begins to go from a solid state to a liquid state — a process called melting. The temperature at which melting occurs is the melting point (mp) of the substance.
What is methane? Where is it found?
Answer:
Methane is an odorless, colorless, flammable gas. It is used primarily as fuel to make heat and light. It is also used to manufacture organic chemicals. Methane can be formed by the decay of natural materials and is common in landfills, marshes, septic systems and sewers
Explanation:
how many atoms are there in 6.8 mole of boron
All atoms of the same element:
have the same number of atoms
have the same number of neutrons
have the same number of electrons
have the same number of protons
Answer:
have the same number of protons
Explanation:
The number of protons in an atom determine what element it is. The number of electrons and neutrons can vary from atom to atom of the element, as long as all the atoms have the same number of protons.
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Why do nitrogen molecules have triple bonds, whereas oxygen molecules have double bonds? How many valence electrons does each atom have, and how does that affect the type of bond formed in each molecule? Draw Lewis dot diagrams to support your answer
Answer:
Nitrogen is a diatomic molecule in the VA family on the periodic table. Nitrogen has five valence electrons, so it needs three more valence electrons to complete its octet. A nitrogen atom can fill its octet by sharing three electrons with another nitrogen atom, forming three covalent bonds, a so-called triple bond.
maybe this will be helpful
mark me brainliest
Answer:
Two covalent bonds form between the two oxygen atoms because oxygen requires two shared electrons to fill its outermost shell. Nitrogen atoms will form three covalent bonds (also called triple covalent) between two atoms of nitrogen because each nitrogen atom needs three electrons to fill its outermost shell.
The number of electrons in an atom's outermost valence shell governs its bonding behaviour. Elements whose atoms have the same number of valence electrons are grouped together in the Periodic Table. ... To form a covalent bond, one electron from the halogen and one electron from another atom form a shared pair.
can someone help and lmk if my answers are correct i don’t think they are please help i’ll give brainliest thank you
Answer:
5=C, every action has an equal or opposite reaction,
6=B, since it has less air drag and more force exerted on it
7= You're correct
Good scientists have what characteristics in common?
Answer:
determination or brains
Explanation:
Which substance gets broken down in a homogeneous mixture?
colloid
solution
solute
solvent
Answer:
Should be Solute
Explanation:
I looked it up ;)
Answer:
c. Solute
Explanation:
What is the mass of a sample containing 3.5 moles of silicon atoms?
28 g
72g
98 g
35 g
How do you solve that with fractions
Answer:
bacon
Explanation:
nator
Answer:
1.57
Explanation:
nator
What is the what is what and why
Answer:
what
Explanation:
is this free points
Where is most of the mass of an atom located? O it is split between the nucleus and the orbits Oin the electrons Oin the nucleus Oin the orbits
Answer:
In the nucleus.
Explanation:
A geologist drew a diagram illustrating a section of a boundary between two
tectonic plates. His diagram includes the geologic feature shown below.
Answer:
pls complete your question
science , thank you for helping !!
Answer:
sksksk
Explanation:
anna oop
Answer:
Try putting Dd okkkkkkkk
Which of the following is an example of chemical weathering?
A. Splitting of rick due to expansion of water
B. Shrinkage of rock when the water is evaporated
C. Erosion due to wind-blown sand
D. Cave formation from the acid in water dissolving limestone
Answer:
d
Explanation:
disolving is a chemical like word and if a limestone cave is forming from the acid in the water thats chemical wheathering!
Answer:
Cave formation from the acid in water dissolving limestone
Explanation: