Answer:
17
Explanation:
you add 19+19 the subtract 21. I think
A potassium isotope contains 19 protons, 19 electrons, and 21 neutrons, so the mass number is 40 as the mass number of the atom is the sum of the protons and the neutrons, the mass number is 40.
What is the significance of the mass number in the atom?The mass number is significant as it is the sum of the number of protons and neutrons present in nucleus of an atom, which determines the atomic weight of an element and also determines its chemical properties and its position on the periodic table. Isotopes of an element have the same atomic number but a different mass number, so they have different properties than the original element.
Hence, a potassium isotope contains 19 protons, 19 electrons, and 21 neutrons, so the mass number is 40 as the mass number of the atom is the sum of the protons and the neutrons, the mass number is 40.
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HELP PLEASE!!!
what is the density of a cube that has the volume of 12mL and a mass of 6g? express in g/mL
Answer:
The density of the cube is 0.5g/mL. Hoped this helped! :)
Explanation:
V= 12.0mL D=M/V
M= 6.0g
D= 6.0g/12.0mL
D= 0.5g/mL
What neutral element has the electron configuration described by the Aufbau diagram above.
Answer:
Aluminium.
Explanation:
The above electronic configuration can be written in a simplified form as shown below:
1s² 2s²2p⁶ 3s²3p¹
Next, we shall determine the number of electrons in the atom of the element as follow:
Number electron = 2 + 2 + 6 + 2 + 1
Number of electron = 13
Next, we shall determine the number of protons.
Since the element is in its neutral state,
The number of electrons and protons are equal i.e
Proton = Electron
Number of electron = 13
Proton = Electron = 13
Proton = 13
Next, we shall determine the atomic number of the element.
The atomic number of an element is simply the number of protons in the atom of the element i.e
Atomic number = proton number
Proton = 13
Atomic number = 13
Comparing the atomic number of the element with those in the periodic table, the element with the above electronic configuration is aluminium since no two elements have the same atomic number.
name two liquid fuels obtained from petroleum
Answer:
Diesel and kerosene.
Hope it helps :)
Answer:
Gasoline
Diesel
Kerosene
LPG
Rethanol
Ethanol
Butanol
A vial is filled with room temperature water, and blue cold water has been placed at the bottom. A warm water bag sits next to the vial. What do you think will happen?
Explanation:
In the context, a vial which is used in store medical samples is filled with water at room temperature. And the vial is kept on a cold water. Also a water bag containing warm water is kept near the vial.
The cold water kept at the bottom of the vial is having lower kinetic energy while warm water will have higher kinetic energy than the others. Since the water in the vial is at room temperature and it is in touch with the cold blue water, the water in the vial will loose or give its temperature to the cold blue water through conduction as well as convection process since temperature always flows from a hot body towards the cold body.
On the other hand, the warm water placed next tot he vial will give its temperature to the atmosphere.
Is beans in water a suspension colloid or solution
Answer:
The CORRECT answer is Solution
Explanation:
Since a Colloid is a liquid like substance that cannot be removed from other solids the only possible choice would be a Solution. becuase with a solution you can drain the solution and still get the beans.
You and your friends were studying lists of spelling and vocabulary lists. It seemed like everyone could easily remember the first word on the list and the fifteenth word on the list. It seemed very hard to remember the words in the middle of the list. What is the hypothesis?
Answer:
you have a bad memory?
Explanation:
Which is classified as an inner transition element?
a) calcium
b) copper
c) fermium
d) helium
How do researchers select a sample that is representative of its population
Explanation:
Using stratified random sampling, researchers must identify characteristics, divide the population into strata, and proportionally choose individuals for the representative sample. ... For example, individuals who are too busy to participate will be under-represented in the representative sample.
Which factor causes a decrease in the rate of dissolution?
decreasing the amount of solute
increasing the stirring of the solution
decreasing the surface area of the solute
increasing the temperature of the solvent
Answer:
The correct option of the first option
Explanation:
Dissolution of a solute in a solution is the process in which the solute interacts with the solvent leading to the disappearance of the solute to form a solution. Rate of dissolution is primarily affected by three factors namely
Stirring of the solution: Stirring the solution causes the solute to interact more with the solvent, thus increasing the rate of dissolution.
Surface area of the solute: The smaller the surface area of the solute, the more easier it is for it (the solute) to interact with the solvent. Hence, the smaller the surface area, the faster the rate of dissolution.
Temperature of the solvent: An increase in temperature of the solvent causes the generally causes more things to dissolve in this solvent due to increased energy of molecules in the solvent, which causes the molecules of the solute and solvent to interact more.
A decrease in the amount of solute will reduce the amount of interaction the solute (since it is in lesser quantity) have with the solvent hence the rate of dissolution will also be low (even though a solution will still be formed).
There are different factors that influences chemical equations. The factor that causes a decrease in the rate of dissolution is decreasing the surface area of the solute.
Dissolution rate is simply known as the transfer rate of some specific drug molecules from the solid particles which is usually crystalline in nature into solution as self free drug molecules. The rate of Dissolution can be determined by the forces of the crystal.Surface area is known to affect the rate of dissolution. Note that When the total surface area of the solute particles is increased, the solute will then dissolves more quickly than ever.
The breaking of a solute into smaller pieces in turn do increases its surface area and increases its rate of solution and the act of stirring, do allows the solute to dissolve faster.
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Who discovered the flame test
Answer:
Thomas Melvill
Explanation:
...
(01.01 MC)
Which of the following could be considered a scientific statement
Answer:
hmmmm not sure and don't know
Explanation:
Thermal radiation emitted by objects allows us to feel infrared
energy as _____
Answer:
THERMAL IMAGING
We can sense some infrared energy as heat. Some objects are so hot they also emit visible light—such as a fire does. Other objects, such as humans, are not as hot and only emit only infrared waves.
2. A block of wood has a mass of 360 grams and a density of 60 g/cm3. What is the volume
of the block of wood?
Answer:
6cm
Explanation:
The volume of the block of wood of 360 grams has been 60 ml or 60 [tex]\rm cm^3[/tex].
The density of an object can be defined as the mass of an object per unit volume. Density plays a pivotal role in the object sinks or floats into a liquid.
If the density of an object is lighter than the density of the liquid, the object will float onto the liquid. If the density of an object is more than the density of the liquid, the object will sink in the liquid.
Density can be given by:
Density = [tex]\rm \dfrac{mass}{volume}[/tex]
Mass of the object = 360 grams
Density = 60 g/[tex]\rm cm^3[/tex]
Volume = [tex]\rm \dfrac{mass}{density}[/tex]
Volume = [tex]\rm \dfrac{360}{60}[/tex]
Volume = 60 [tex]\rm cm^3[/tex] .
1 [tex]\rm cm^3[/tex] = 1 ml
Volume = 60 ml.
The volume of the block of wood of 360 grams has been 60 ml or 60 [tex]\rm cm^3[/tex].
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¿por qué entre el calcio (Ca) que pertenece al segundo grupo y el galio (Ga) que pertenece al tercer grupo hay 10 elementos, ¿Que nombre reciben estos elementos?
Answer:
Estos elementos se denominan metales de transición, metales pesados, elementos del bloque D, etc.
Explanation:
Aquí, en esta pregunta, queremos saber la razón por la cual hay un espacio de 10 elementos entre el calcio, que es un elemento del grupo dos, y el galio, que es un elemento del grupo 3.
Al observar la tabla periódica, la tabla periódica moderna, notamos un bloque de elementos entre los elementos del grupo 2 y los elementos del grupo 3 en la tabla periódica.
Entonces, ¿por qué se colocan estos elementos entre ambos grupos? Se colocan aquí porque no pertenecen en su totalidad al grupo 2, ni tampoco al grupo 3.
Estos elementos presentan una especie de estados de oxidación variables que son responsables de una amplia variedad de propiedades comunes entre ellos.
A metal ‘X’ has high melting point, good conductor of electricity, and is most malleable. Then the metal ‘X’ is A) Cu B) Au C) Fe D) Pt
Answer:
A) Cu
(copper)
During dialysis, water and urea pass from the blood into the dialysis fluid. Proteins stay in the blood.
(a) Name the process by which water passes from the blood to the dialysis fluid.
(b) Describe the process you have named in (a).
(c) Explain why water passes out of blood but proteins do not.
Answer:
Healthy kidneys clean your blood and remove extra fluid in the form of urine. They also make substances that keep your body healthy. Dialysis replaces some of these functions when your kidneys no longer work. There are two different types of dialysis - hemodialysis and peritoneal dialysis. The following is about hemodialysis.
If you burn a piece of wood, it becomes a different substance. What type of
property is this?
A. Electrical property
O
B. Chemical property
C. Physical property
D. Mechanical property
Answer:
B. Chemical property
Explanation:
Answer:
B
Explanation:
a reaction has taken place in which you can't get back what you started with
The cell organelles that contains chlorophyll
Answer:
In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.HELP PLS!!!!!!! NEED THIS IN 5 MINS
2. What kind of bond is pictured in the diagram to the left? Describe the movement of the valence electrons in the bond above? (Hint: Sharing or giving up?)
in a complete sentence pls
Answer:
Sharing or covalent bonding is taking place.
Explanation:
The valence electron will be shared by both the atoms so that means that the election will move around both of the atoms.
HELP PLZ !!!!! !!!!
Which of these is a sedimentary rock?
A) Granite
B) Obsidian
C )Quartzite
D) Sandstone
Answer:
D
Explanation:
In chemistry she wants to know why to certain items or people shock me?
Neutrons have a
charge?
neutral
negative
positive
Answer:
Neutrons have a neutral charge
Explanation:
A neutron consists of 3 quarks, 1 up and 2 down. The up quark has a charge of + 2/3e, and the down quarks each have a charge of - 1/3e. So, the charges on the 3 quarks tend to cancel out to produce a neutrally charged particle.
If you had zinc and copper and melted it down into uranium what would happen? I will mark brainliest
Answer: Major radioactive elements (such as uranium) break down and create lead as one of ... Exposure to even small amounts of lead can be harmful since lead has no use in the body. ... of all industrial metals in the world because lead is easily re-melted and refined. ... Other metals that are found with zinc are silver and copper.
Explanation:
Claudia performed a flame test in her lab. The result of her flame test is shown here.
Answer:
Where is the results and what is the question or is there a picture
Explanation:
what happens during covalent bonding?
Answer:
The atoms share some of their outer electrons so that each atom has a stable noble gas arrangement.
Explanation:
Convert 30°C into kelvin
Answer:303.15
Explanation:
The loops in Ptolemy’s model, and those shown on the video, are called motion. This phenomenon is caused by Earth’s orbit than those of other planets.
Answer:
The loops in Ptolemy’s ✔ geocentric model, and those shown on the video, are called
✔ retrograde motion. This phenomenon is caused by Earth’s
✔ faster orbit than those of other planets.
Explanation:
Answer:
✔ geocentric
✔ retrograde
✔ faster
Explanation:
When dealing with Atoms, what does MAN mean?
Answer:
when dealing with atoms man means man-made because man means man-made
What volume is equivalent to 14,000 mm cubed
Answer:
14mL
Explanation:
1mL = 1cm^3, 1000mm^3 = 1000cm^3
ANALYSIS
1. Why are resources like air and water considered to be at risk, even though
they are considered renewable?
Answer:
The pollution can cause resources to lessen.
Due to pollution, resources like air and water considered to be at risk, even though they are considered renewable.
What is pollution?Pollution is the presence on an environment or substance, harmful substances that are dangerous to the living organisms found in that environment.
Water and air pollution is a serious risk to human, animal and plant life in the environment.
Therefore, due to pollution, resources like air and water considered to be at risk, even though they are considered renewable.
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