Answers
Al= 3
Rb= 1
Kr= 8
Related Questions
Potasyum-40 küçük atom numaralı doğal radyoaktif birkaç element izotopundan biridir ve doğada K izotopları içerisindeki bolluk yüzdesi %0,012'dir. 1,65 mg K/mL içeren bir bardak sütü içtiğiniz zaman kaç tane 40K atomu yutmuş olursunuz? (1 Bardak süt 225 mL, K: 39,10 g/mol)
Answers
Answer:
6.707 × 10¹⁷
Explanation:
From the information given:
40 ^ K kütlesi = sütteki K kütlesi × 40 ^ K / 100 kütle yüzdesi
nerede;
sütteki K kütlesi = 1.65 mg of K/mL × 225 mL = 371.25 mg of K
∴
40 ^ K kütlesi = 371.25 × 0.012/100
40 ^ K kütlesi = 0,04455 mg = 4.455 × 10⁻⁵ grams
40 ^ K mol sayısı = 40 ^ K kütlesi / molar kütle
= 4.455 × 10⁻⁵/40
= 1.11375 × 10⁻⁶
Son olarak, 40 ^ K = mol × Avogadro sayısı atomları
= 1.11375 × 10⁻⁶ × 6.022 × 10^23
= 6.707 × 10¹⁷
What is the name of the family with an oxidation number of +2?
a. Halogens
b. Alkali Earth Metals
c. Noble Gasses
d. Transition Metals
Answers
Answer:
Alkali Earth Metals
Explanation:
The oxidation number is equal to the charge which is determined by the valence electrons. Alkali Earth Metals all have 2 valence electrons and, therefore, an oxidation number of 2.
Answer:
+2alkaline earth metal and +1 oxidation number is alkali metal
Explanation:
alkali is Arabic word means ash
How might water high specific heat capacity affect energy distribution and temperature on earth
Answers
Answer:
Water can hold a lot of heat inside it and as the climate starts getting cold, the water releases the heat which heats up the climate
Due to the fact that water has a high heat capacity, its temperature has a very limited range, which causes the coastal areas close to having a similar small daily and seasonal temperature range.
What is specific heat capacity?"When the temperature of a material rises 1 K (or 1 °C), the amount of heat (J) absorbed per unit mass (kg)".
When the weather begins to grow chilly, water releases the heat it has stored inside, warming the environment.
High specific heat of the water makes it temperature resistant, and it helps the earth to maintain its temperature and helps organisms to maintain their functions at a constant temperature of the earth.
Thus, the normal temperature is necessary for maintaining the temperature of the earth and the water bodies maintain the temperature of the earth.
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HELPPPPPPPPPPPPPPPPPPP
Answers
Answer:
not sure about the first one, but i know SDS provides information about the last 3.
Explanation:
Help please When you are measuring your pulse (heart beats per minute) what system are you monitoring?
A. Digestive
B. Respiratory
C. Circulatory
D. Integumentary (skin)
Answers
True or false
Equal forces acting on one object in opposite directions are called balanced forces
Answers
Answer:
True
Explanation:
Forces, equal in magnitude and opposite in direction, and cancel each other out are called Balanced Forces.
Balanced Forces DO NOT cause any change in the velocity of the object, but the Object may correspond to a change in shape or size.
Example :
Blasting a balloon by compressing it tightly with both hands, roughly with an equal force, is a practical example of Balanced Forces. In this case, the balloon before the burst stays at a state of rest and same after the burst. But the burst or the compression, causes a change in the shape of the balloon.
Question:
In a laboratory demonstration, a balloon filled with methane and oxygen was exposed to a
flame. The result was a brief, large flame. The students were asked to formulate an equation for
the reaction. One answer is below.
CH, + 0 = CO,
This equation is incorrect.
A. Explain how and why it is incorrect
B. What would the correct equation be, and how do you know that?
Answers
Answer:
The laboratory demonstration consists of the following;
The compounds present in the combustion reaction = Methane, CH₄ and Oxygen, O₂
The chemical equation for the combustion reaction is given as follows;
CH₄ + 2O₂ → CO₂ + 2H₂O
Therefore;
A. The equation given as CH₄ + O → CO₂ is not correct because;
1) Oxygen gas exist as diatomic molecules, O₂, and given that the experiment involves the mixture of gases, the oxygen gas present which can exist as a separate compound, should be represented as O₂
2) The number of oxygen molecules in the reaction is two rather than one
3) The product also includes two molecules of water (vapor) H₂O
B. The correct equation for the reaction should be given as follows;
CH₄ + 2O₂ → CO₂ + 2H₂O
B i) The constituents of the equation is obtained by the knowledge of the fact that the combustion reaction of an organic substance such as methane in the presence of oxygen yields, carbon dioxide and water (vapor)
The equation showing the relative amounts the reacting compounds is by balancing the basic equation of the combustion of methane in the presence of oxygen
Explanation:
balancing equations help!!
Answers
2) 2KClO3–> 2KCl+3O2
3) 2NaCl+F2–> 2NaF+Cl2
4)Pb(OH)2+ 2HCl—> 2H2O+PbCl2
5) 2AlBr3+ 3K2SO4–> 6KBr+Al2(SO4)3
6) is already balanced
If you have any questions just let me know :)
Does anyone know how to determine if a reaction is a redox or not?
2Ca+O2→2CaO2 is the reaction. I've already made it a balanced equation, I just need to determine if its a redox or not.
Thank you!
Answers
The reaction is included in a redox reaction
Further explanation:
Given
Reaction
2 Ca + O₂ → 2 CaO
Required
a redox reaction
Solution
Redox reactions are reactions where there is a change in oxidation number
Oxidation is an increase/increase in oxidation number, while reduction is a decrease/decrease in oxidation number.
Reducing agents are substances that experience oxidation and oxidizing agent are substances that experience reduction
in the above reaction is included in a redox reaction because there is a change in oxidation number
Ca⇒Ca²⁺+ 2e⁻(for balanced equation : 2Ca⇒2Ca²⁺+4e⁻)
Oxidation ( 0 to +2)
O₂+2e⁻⇒O²⁻(for balanced equation : O₂+4e⁻⇒2O²⁻)
Reduction (0 to -2)
What energy is formed when you put your hands together and rub them up and down rapidly
Answers
Answer:
When you rub your hands together thats mechanical energy. Once you hands warm up its heat energy.
What is the redox reaction? And how does the redox reaction happen inside batteries?
Answers
Answer:
It is called a reduction-oxidation, oxide-reduction reaction, or simply as a redox reaction, any chemical reaction in which one or more electrons are transferred between the reactants
Redox battery is an example of both a Flow Battery and a two electrolyte system.In this case, it depends on two different active aqueous electrolytes of vanadium dissolved in sulfuric acid separated by a membrane at which ionic interchange takes place.
Thats my opinión though.
FOR 35 POINTS & A BRAINIST*
1.) For an atom of sulfur, there are
A.) two electron shells with 6 valence electrons
B.) three electron shells with 6 valence electrons
C.) four electron shells with 6 valence electrons
D.) five electron shells with 6 valence electrons
2.) Which atom has four electron shells with 7 valence electrons?
A.) F
B.) CI
C.) Br
D.) I
3.) Which atom has three electron shells with 8 electrons in its outermost orbit?
A.) He
B.) Ne
C.) Ar
D.) Kr
4.) Which method should be used to draw electrons that are involved in a collision during a chemical reaction?
A.) Bohr's model
B.) Lewis dot model
C.) Addition model
D.) Subtraction model
Answers
2.) C
3.) C
4.) B
I genuinely double checked that these were right! I hope it helps!!
Using the model of the periodic table, which element pictured represents an unreactive gas?
Answers
Answer:
2
Explanation:
Nobel gasses are not reactive and are the far right group on the periodic table. This is because they have a full valence electron shell which is the most stable electron configuration. Most reactions occur in order for an atom to fill its valence shell and since they already have a full valence shell there is no reason for them to react.
Compared to ionic compounds, molecular compounds generally have
A. good conductivity.
B. greater densities.
C. more chemical bonds.
D. a low boiling point.
Answers
Compared to ionic compounds, molecular compounds generally have a low boiling point and the correct option is option D.
What are Molecular compounds?
Molecular compounds are held together by covalent bonds. They are also called covalent compounds.
Covalent bonds are responsible for many of the properties of covalent compounds. Covalent compounds have relatively low boiling points, cannot conduct electricity, and may not dissolve in water.
Unlike ionic compounds, covalent compounds do not have freely moving electrons, so they cannot conduct electricity.
The individual molecules of covalent compounds are more easily separated than the ions in a crystal, so most covalent compounds have relatively low boiling points.
Therefore, compared to ionic compounds, molecular compounds generally have a low boiling point and the correct option is option D.
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is combustion an example of the law of conservation of matter and why?
Answers
Answer:
Explanation:
The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. For example, when wood burns, the mass of the soot, ashes, and gases, equals the original mass of the charcoal and the oxygen when it first reacted.
Can someone define these for me
Answers
Answer:
These are all in order....
Explanation:
- closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system
- a solute is a substance dissolved in another substance, known as a solvent
- A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid
- a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent)
- a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy
- a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
- Half-life is the time required for a quantity to reduce to half of its initial value
- the determination of the age or date of organic matter from the relative proportions of the carbon isotopes carbon-12 and carbon-14 that it contains. The ratio between them changes as radioactive carbon-14 decays and is not replaced by exchange with the atmosphere.
- any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed
Form a bond: Each electron has a charge of 1–, and each proton has a charge of 1+. You can calculate the charge of an atom by subtracting the number of electrons from the number of protons. Move an electron from the sodium to the chlorine atom.
1. Sodium has a charge of 1+ and chlorine has a charge of 1-
2. Chlorine has a charge of 1+ and sodium has a charge of 1-
3. Both atoms have a charge of 1+
4. Both atoms have a charge of 1-
Answers
Answer:
1. Sodium has a charge of 1+ and chlorine has a charge of 1-
Explanation:
Sodium has 11 protons and 11 electrons. If you remove one electrons we now have only 10 electrons.
Hence; number of protons - number of electrons = 11 - 10 = +1
Sodium has a charge of +1
Chlorine has 17 electrons and 17 protons. if it gains 1 electron then it now has 18 electrons.
Hence; number of protons - number of electrons = 17 - 18 = -1
Chlorine has a charge of -1
What is the molar mass of B,(Croa)g?
a. 186 g/mol
b. 369 g/mol
C. 232 g/mol
d. 250 g/mol
Answers
write all products and relevant tests and observations when KOH reacts with NH4NO3
Answers
Answer:
get a bucket and a mop that's a wap that's wap I'm talking wobble wobble wobble that's a wap
Which element has a mass number of 32?
a. argon ion
b. silicon ion
C. silicon
d. sulfur
Answers
Condensation point and freezing point of argon in KELVIN.
Answers
Answer:
Condensation: 423.3 K
Freezing: 83.96 K
(this is all i could figure out :) hope it helps)
What is the advantage of using Microsoft Excel to create a graph, as opposed to pen and paper?
Chemistry class I NEED HELP FAST
Answers
Answer:
the advantage of using Microsoft Excel to create a graph, as opposed to pen and paper is it will help you get the right answer
Explanation:
WHEN A SOCCER PLAYER KICKS A BALL, THE BALL ACCELRATES. EXPLAIN WHAT CAUSES THIS ACCELERATION IN TERMS OF FORCES?
EXPLAIN WHAT HAS A GREATER INERTIA- A SPEEDING CAR OR A JET AIRPLANE SITTING ON A RUNWAY.
DO FORCES ALWAYS CAUSE MOTION? EXPLAIN
DESCRIBE THREE EXAMPLES FROM SPORTS IN WHICH A FORCE CHANGES HE VELOCITY OF AN OBJECT OR A PERSON.
Answers
Answer:
When we kick the ball, the force we apply to it causes it to accelerate from a speed of 0 to a speed of dozens of kilometers per hour. When the ball is released from the foot, it begins to decelerate (negative acceleration) due to the force of friction that is exerted upon it (as we observed in the previous example).
Explanation:
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over
the next few minutes?
O Molecules in both the metal and the surrounding air will start moving at lower speeds.
O Molecules in both the metal and the surrounding air will start moving at higher speeds.
O The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
O The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answers
Answer:
It would be the third answer.
Explanation:
This is because over the next few minutes, the heat would radiate away from the atoms in the metal plate and the atoms around the plate would absorb this radiation.
which of these is a characteristic
of index fossils
Answers
Answer: A index fossil is any animal or plant preserved in the rock record of the earth that is characteristic of a particular span of geologic time or environment. A useful index fossil must be distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time.
Explanation:
Which Ion has the same electron configuration as an Ar atom
1. Cl -
2. F -
3. Li+
4. Na +
Answers
Cl- would give you 18 electrons
F- would give you 10 electrons
Li+ would give you 2 electrons
Na+ would give you 10 electrons
Cl- would be the correct answer
Show your work with good use of units, rounding, and significant figures. [Hint: it is good practice to show the value of your answer before you round off to the final answer with the correct significant figures!]
(8 points) How much heat is required to convert 10.00 g of ice at –20.00°C to water at 25°C. The specific heat of ice is 2.09J/g°C; the specific heat of water is 4.182 J/g°C; the heat of fusion is 333.0 J/g.
Group of answer choices
Answers
Heat required : 4.8 kJ
Further explanationThe heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C
[tex]\tt Q=10\times 2.09\times (0-(-20)=418~J[/tex]
2. phase change(ice to water)
[tex]\tt Q=10\times 333=3330~J[/tex]
3. heat to raise temperature from 0 °C to 25 °C
[tex]\tt Q=10\times 4.18\times (25-0)=1045~J[/tex]
[tex]\tt Q~tot=418+3330+1045=4793~J\rightarrow rounding~and~2~sig~figs=4.8~kJ[/tex]
A boundary between air masses that don't move possibly causing rain for several days.
Answers
Answer:
A Front
Explanation:
A Front is a boundary between two air masses of different density, moisture, or temperature
two negative charges are placed near each other. what happens between the charges
Answers
Answer:
repulsion
Explanation:
Answer:
Explanation:
In contrast to the attractive force between two objects with opposite charges, two objects that are of like charge will repel each other. ... Similarly, a negatively charged object will exert a repulsive force upon a second negatively charged object. Objects with like charge repel each other.
how many dots would a dot diagram for selenium, one of the group 16 elements, have?
Answers
Answer:
Because selenium is in the 16th column on the periodic chart, it has 6 valence electrons. Thus, the Lewis structure (or electron dot structure) for selenium has 6 dots around it.
It will look similar to this without the underscores:
__.
. Se:
_. .
Explanation:
The Lewis structure (or electron dot structure) for selenium has 6 dots around it.
What is an electron dot structure?Electron dot diagrams are diagrams in which the valence electrons of an atom are shown as dots distributed around the element's symbol.
Selenium is in the 16th column on the periodic chart, it has 6 valence electrons. Thus, the Lewis structure (or electron dot structure) for selenium has 6 dots around it.
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