Answer:
A. Silicon
Explanation:
The ability of an atom to attract electrons is known as electronegativity.
Electronegativity is the measure of the relative tendency with which the atoms of the element attract valence electrons in a chemical bond.
Across a period from left to right, the ability to attract electrons increases. Down a group, the ability decreases. Silicon is to the left most part and it will have the the least ability to attract electrons.The first mass extinction that occurred between the Paleozoic and the Mesozoic Era,
caused the extinction of which organism?
O Wooly mammoth
O Dinosaurs
O Trilobites
Flying Reptiles
Answer:
O Trilobites
Explanation:
The first mass extinction that occurred between the Paleozoic and the Mesozoic era caused the extinction of the trilobites.
Extinction are catastrophic events that causes the loss of organisms on the earth surface. Several factors can lead to extinction.
The first mass extinction took place between the Paleozoic and the Mesozoic era. This wiped out one of the most successful organism on the earth surface at that time. They were the trilobites.Give the symbol for the element with the following orbital diagram:
↑↓
1s
0000
↑↓
2s
0000
↑↓
↑↓
2p
↑↓
0000
↑↓
3s
0000
↑↓
↑↓
3p
↑↓
0000
↑↓
4s
0000
↑↓
↑↓
↑↓
3d
↑↓
↑
The given orbital diagram are iron and symbol for the element is Fe
Orbital diagrams are a pictorial description of electrons in an atom and where electron go in atom then we have to follow three rules, and the first one being the Auf bau Principle, the Auf bau Principle states that each electron occupies the lowest energy orbital first filled and the second is pauli exclusion principle in which only two electron are present which is in opposite spin and third is hunds rule of maximum multiplicity in which pairing of electron is not possible until orbital are singly occupied this rules are used for filling the electron here given orbital diagram in which 1s²2s²2p⁶3s²3p⁶4s²3d⁶ means the element is iron and symbol of this element is Fe
Know more about orbital diagram
https://brainly.com/question/20672248
#SPJ1
Can compounds be broken down into the elements they are made of?
Answer:
yes, some can
Explanation:
because like salt an other compounds by being decomposed
How many grams of C3H8 are in a 7 L tank at 293 K and 5.45 atm?
Lava that cools quickly forms: A. basalt B. granite C.quartz D. none the above
Answer:
I think the answer would be B. hope this helps!!
Explanation:
4. When the mole fraction of solute is 1, there is
(a) a 1:1 ratio of solute to solvent.
(b) no solute present.
(c) only solute present.
(d) only solvent present.
(e) 1 mole of solute and 99 moles of solvent.
Answer:
(c) only solute present
Explanation:
In chemistry, the mole fraction, denoted by X, refers to the number of moles of a substance in a compound/mixture divided by the total number of substances in the same compound or mixture.
In this case, we can say that mole fraction represents the number of solutes to the number of solutes and solvent in the solution i.e. X = nA/nA + nB
Where; nA = number of solutes
nB = number of solvent
X = mole fraction.
Based on this analogy, When the mole fraction of solute is 1, there is only solute present. That is; X = 1 / 1 + 0
X = 1/1 = 1.
chemistry question help please
Answer:
xii. B. Smelting
xiii. D. Carbon
Explanation:
Smelting is known to be a process by which a metal is gotten. It is gotten either as the element or as a simple compound. This is obtained from metal's ore by heating. The heating can be done ordinarily in the presence of oxidizing agents, like air, or reducing agents, carbon e.g coke.
Zinc is gotten after Zinc oxide is heated in the presence of carbon.
This process is smelting.
Concentrated tetraoxosulphate acid is a strong dehydrating agent. It has the ability to char wood, paper, or sugar, leaving a carbonaceous residue. The charring effect is as a result of the carbon that is found in the wood.
The acid sucks in the oxygen and hydrogen, leaving behind the carbon; this results in the charring effect.
What do the red arrows represent
Answer:
There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.
Complete the graphic organizer.
Basic Parts of an Atom
Answer:
I'm not sure but I think the answer is electrons, protons and neutrons.
A 1,600-milliliter bucket of paint is at a temperature of 70°F. Then the paint is divided equally into four smaller buckets. Each bucket is at 70°F before the paint is poured.
the temperature of each 400 milliliter bucket is about _____ the temperature of the original bucket of paint.
a.the same as
b.four times
c.one fourth
science
Answer:
a.the same as
Explanation:
The temperature of each 400mL bucket is about the same as the temperature of the original bucket of paint.
This is because the temperature of the paint inside the bucket is not dependent on the amount of paint present.
In this regard, the temperature is an intensive property. So each of the boxes will have a temperature that is the same as that of the original bucket. Each of the particles have the same amount of kinetic energy.Write a chemical equation of Dr. Jeff's demonstration using a battery to light steel wool on fire. The battery is used to allow a current to travel through the steel wool, thus heating it. Steel wood is made from iron (Fe).
Answer:
2Fe(s) + 3O2(g) --------> 2FeO3(s)
Explanation:
According to the question, a battery was used to light the steel wool by bringing the terminals very close together. When the battery came into contact with the steel wool, current was sent out through the thin wire. This caused the iron to heat up quite well.
Iron reacts with oxygen under these conditions as follows;
2Fe(s) + 3O2(g) --------> 2FeO3(s)
This is the chemical reaction that occurs when the steel wool is set on fire.
Chemical equation involved in Dr. Jeff's demonstration is
2 Fe+3 O₂[tex]\rightarrow[/tex]2 FeO₃
What is the effect of heating in chemical reactions?Battery is a device which helps in conduction of current. When a battery is used to pass a current through a substance in this case which is steel wool made up of iron it starts getting heated up.
The amount by which substance gets heated up is directly proportional to the current passing through it. As more current is passed through the battery it gets heated more.
During heating, the iron present in the steel wool reacts with oxygen to form iron oxide with iron present in the+3 oxidation state.When the heat exceeds a certain point the steel wool catches fire due to the heat generated. The heat causes the electrons present in steel wool of iron to move faster and collide with each other thus generating more heat.
Learn more about effect of heat in chemical reactions:
https://brainly.com/question/487518
#SPJ2
Hydrogen bonds are in the family of Van der Waals forces. They are weaker than ionic and covalent bonds but they cause interesting changes with different chemicals.
What is one of the changes that hydrogen bonds are responsible for?
A. Cause DNA has the double helix shape.
B. Causes salts quickly dissolve in water.
C. Cause sugar looks like a crystal.
D. Cause liquid H2O to have a larger volume than frozen (solid) H2O
Answer:
The answer is B. Van der Waals forces are weaker than ionic and covalent bonds.
Explanation:
In general, if we arrange these molecular forces from the strongest to weakest, it would be like this:
Covalent bonds > Ionic bonds > Hydrogen bonds > Dipole-Dipole Interactions > Van der Waals forces
Covalent bonds are known to have the strongest and most stable bonds since they go deep and into the inter-molecular state. A diamond is an example of a compound with this characteristic bond.
Ionic bonds are the next strongest molecular bond following covalent bonds. This is due to the protons and electrons causing an electro-static force which results to the strong bonds. An example would be Sodium Chloride (NaCl), which when separated is Na⁺ and Cl⁻.
Van der Waals forces, also known as Dispersion forces, are the weakest type of molecular bonds. They are only formed through residual molecular attractions when molecules pass by each other. It doesn't even last long due to the uneven electron dispersion. It can be made stronger by adding more electrons in the molecule. This kind of molecular bonds appear in non-polar molecules such as carbon dioxide.
HOPE THIS HELPS!!!!!!!!!!!!!!
///////////////////////////////////////////////////////////////////////////////////////////
The change that Hydrogen Bonds are most likely responsible for would be:
B). Causes salts to quickly dissolve in water.
As per the details provided, the hydrogen bonds are classified into the category of Van der Waals forces and the primary reason behind this has been that it leads salt to solvate immediately in the water. Amongst all the bonds, covalent bonds are characterized as the toughest while ionic bonds and hydrogen bonds are followed by it in terms of strength.The reason for which hydrogen bonds cause the change of allowing salts to dissolve immediately is that it illustrates a weaker strength of molecules due to its formation with residual uneven construction.Thus, option B is the correct answer.
Learn more about 'Covalent Bonds' here:
brainly.com/question/10777799
After what part of the cell cyle does the cell begin interphase?
A.anaphase
B.prophase
C.cytokinesis
Explanation:
The prefix inter- means between, reflecting that interphase takes place between one mitotic (M) phase and the next. Image of the cell cycle. Interphase is composed of the G1 phase (cell growth), followed by the S phase (DNA synthesis), followed by the G2 phase (cell growth).
1. Which of the following is the amount of space that an object takes up?
1. density
2. volume
3. mass
Answer:
2. volume
Explanation:
Answer:
volume
Explanation:
what is the empirical formula 63.0 g Rb and 5.90 g O.
Answer:
Explanation:
1st convert given data into % per 100wt...
Total system mass = 63.0g + 5.90g = 68.9g
%Rb = 63.0g/68.9g x 100% = 91.4% per 100wt
%O = 5.9g / 68.9g x 100% = 8.6%
Then follow the following sequence of calculations...
% => grams => moles => mole ratio => reduce to smallest whole no ratio => empirical ratio => empirical formula
%Rb = 91.4% => 91.4g/ 85.5g·mol⁻¹ =>1.069mole
%O = 8.6% => 8.6g/16g·mol⁻¹ => 0.5375mole
Rb:O => 1.069 : 0.5375
Reduce by dividing by the smaller mole value
1.069/0.5375 : 0.5375/0.5375 => 2 : 1 <=> empirical ratio
∴ Empirical Formula => Rb₂O
How many formula units are in 2.58 moles of Caci.?
Answer:
1.55 x 10²⁴ formula units
Explanation:
Given parameters:
Number of moles of CaCl₂ = 2.58moles
Unknown:
Formula units in the compound = ?
Solution:
To solve this problem, we must understand that;
1 mole of a substance contains 6.02 x 10²³ formula units
2.58 moles will contain 2.58 x 6.02 x 10²³ formula units
= 1.55 x 10²⁴ formula units
A compound XO exists in nature. A scientist wanted to prepare the same compound in his lab based on the law of constant proportion but the formula of the compound that he prepared was found to be XO2. Which postulates of the law of constant proportion did he violate?
Answer:
The postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
Explanation:
The law of constant composition (or definite proportion) states that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
This law implies that irrespective of the source of the sample of the compound or the method by which the sample was prepared, as long as the sample is pure, the elements present in the compound are always combined in a specific ratio by mass. For example, water has the molecular formula H₂O. Irrespective of the water source, for example, tap-water, lake, stream, river or rainfall, each pure sample of water will have the constant composition of 2 atoms of hydrogen to one atom of oxygen.
The given compound exists as XO in nature. Therefore, irrespective of the source or method of preparation, every sample of this compound should have the formula XO. Since the compound prepared by the scientist was XO₂, therefore, the postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass was violated by the scientist. The scientist must have prepared a different compound of the elemental compositions.
Daffodil is ordering office supplies for her company. When she tries to order pencils, she finds that pencils are sold by the gross, which is equal to 144 pencils. Daffodil checks how many pencils her company uses in a year, and decides to order 5 gross of pencils. How many pencils will she receive? Remember to include units (full word, plural, WATCH YOUR SPELLING) as they are worth half of this question.
Answer:
720 pencils
Explanation:
The parameter given are;
The unit quantity by which the pencils are sold = 1 gross
The number of pencils Daffodil orders = 5 gross of pencils
One gross is a quantity equal to twelve dozens
Therefore, we can write;
1 gross = 12 × 12 = 144
From which we have;
5 gross = 5 × 144 = 720
Which gives;
For the 5 gross of pencils Daffodil orders, she receives 720 pencils
Which pair of compounds has the same empirical formula? C₂H₂ and C₆H₆ C₂H₆ and C₃H₆ C₂H₅OH and CH₃OH CH₃CHO and C₃COOH
Pair of compounds have the same empirical formula :C₂H₂ and C₆H₆
Further explanationGiven
Carbon compound
Required
The same empirical formula
Solution
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
C₂H₂ and C₆H₆
Empirical formula CH
(CH)₂=C₂H₂
(CH)₆=C₆H₆
C₂H₆ and C₃H₈
C₂H₆: Empirical formula CH₃
C₃H₈: Empirical formula C₃H₈
C₂H₅OH and CH₃OH ⇒ Empirical formula
CH₃CHO: Empirical formula : CH₃CHO
CH₃COOH: Empirical formula CH₂O
_____ are factors that are not tested and remain constant. A. Dependent variables B. Controlled variables C. Independent variables D. Constant variables
Answer:
B. Controlled variables
Explanation:
The Dependent sample t-test compares the mean score of measurements in one group to that of another other group. It mainly used when analyzing comparable sample units as it pairs repeatable observations within a time frame.
Controlled variables are factors that are not tested and remain constant. Some examples of controlled variables are temperature, pressure, volume etc
How many carbon atoms are represented by the model below?
Answer:
3
Explanation:
Determine the empirical formula for a compound with 68.4% Cr and 31.6% O. Show your work in the space below.
Answer:
Cr2O3
Explanation:
To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:
68.4% Cr = 68.4g of Chromium
31.6% O = 31.6g of Oxygen
Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.
Cr = 68.4/52 = 1.315 mol
O = 31.6/16 = 1.975 mol
- Next, we divide each mole value by the smallest value (1.315mol)
Cr = 1.315/1.315 = 1
O = 1.975/1.315 = 1.50
The ratio or Cr to O is 1:1.5
We multiply this ratio by 2 to get the whole number ratio as follows:
2 × 1: 2 × 1.5
2:3
Hence, the empirical formula of Cr and oxygen is Cr2O3.
Can someone help me please :)
What happens when the compound Mgo is formed? (5 points)
Oxygen transfers two electrons to magnesium.
Oxygen receives two electrons from magnesium.
Magnesium forms an ion with -1 charge; oxygen forms an ion with +1 charge.
Magnesium forms an ion with +1 charge; oxygen forms an ion with -1 charge.
Answer:
Oxygen receives two electrons from magnesium.
Explanation:
Hello!
In this case, considering the chemical reaction by which magnesium oxide is produced:
[tex]2Mg+O_2\rightarrow 2MgO[/tex]
In that case, if we show up the oxidation states, we have:
[tex]2Mg^0+O_2\rightarrow 2Mg^{2+}O^{2-}[/tex]
In such a way, since metals, like magnesium, have the capacity to lose electrons, rather than receive them, we infer why it turns out with +2 rather than -2; thus, we the correct answer is "oxygen receives two electrons from magnesium." because it results with -2 in MgO.
Best regards!
Answer:
Oxygen receives two electrons from magnesium.
Explanation:
What is a sign that a person may be abusing drugs?
A a change in mood and behavior
B avoiding friends and family members
C a drop in grades and a loss of interest in activities
D all of the above
Answer:
answer is a because drugs do so to the person.
What is the energy of a photon with a frequency of 5.90 × 10¹⁴ s⁻¹? (h = 6.626 × 10⁻³⁴ J • s)
How many moles are 21.67 L of NH4CI?
Type your answer...
Answer:
0.967mole
Explanation:
Given parameters:
Volume of NH₄Cl = 21.67L
Unknown:
Number of moles = ?
Solution:
We assume that the volume was taken at standard temperature and pressure,
Then;
Number of moles = [tex]\frac{volume }{22.4L}[/tex]
Number of moles = [tex]\frac{21.67}{22.4}[/tex] = 0.967mole
“Copper pots are the best pots for cooking food quickly.” Which term best describes this statement?
Answer:
because I make eggs and they taste delicious
Answer:
Conclusion
Explanation:
Please dear lord help me I can’t solve it
If 11 grams of a gas occupies 5.6 liters at STP, what is its gram molecular mass?
The molecular mass of gas = 44 g/mol
Further explanationGiven
5.6 Liters of gas
11 gram of gas
Required
The molecular mass
Solution
STP = Standart Temperature and Pressure , 1 atm 273 K
At STP , 1 mol gas = 22.4 L
So mol of 5.6 Liters gas :
= 5.6 : 22.4
= 0.25 moles
The molecular mass of gas :
= mass : mol
= 11 g : 0.25 moles
= 44 g/mol
