Complete Question:
In order to help visualize an atom, a scientist may do which of the following?
Group of answer choices
A. Form a hypothesis.
B. Make a model.
C. Create a law.
D. Develop a theory.
Answer:
B. Make a model.
Explanation:
An atom can be defined as the smallest unit of matter and it retains all the chemical properties associated with the element.
Basically, atoms are the building block of matters and essentially comprises of three (3) fundamental particles which are protons, neutrons and electrons which typically determines the charge and mass of an atom.
In order to help visualize an atom, a scientist may make a model. Due to the limitations of various human inventions in the field of science, it has become practically impossible to get an image or a picture of an atom even through the use of a microscope because of its minute nature and owing to the fact that it is much smaller than the wavelength of visible light.
However, some notable scientists have created or developed models that aids in the understanding and visualization of atoms. These atomic models are;
1. Quantum mechanics model of atom.
2. John Dalton's atomic model.
3. Neil Bohr's atomic model.
4. Rutherford's model of the atom.
5. Thomson's model of the atom.
6. Plum pudding atomic model.
explain why the reaction between lead (II) nitrate and concentrated sulphuric (VI) acid starts and stops immediately?
Answer:
The reaction produces insoluble lead (II) sulphate which coats the surface of lead (II) nitrate [Pb(NO3)]
Which of the following most likely happens when thermal energy is removed from a chemical reaction?
Answer:
fewer collisions occur between particles or lowering the temperature
Explanation:
A helium balloon in a closed car occupies a volume of 1.32 L at 30.0°C. If the car is parked on a hot day and the volume of the balloon increases to 2.50 L what is the temperature in the car, assuming the pressure remains constant?
Answer:
T₂ = 573.86 K
Explanation:
Given data:
Initial volume = 1.32 L
Initial temperature = 30.0°C (30+273 = 303 K)
Final volume = 2.50 L
Final temperature in car = ?
Solution:
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₂ = V₂T₁/V₁
T₂ = 2.50 L × 303 K / 1.32 L
T₂ = 757.5 L.K / 1.32 L
T₂ = 573.86 K
Help me with homework.
The chemical equation is said to be balanced if the number of atoms in the reactants and products is the same
Further explanationEquation balanced ⇒ total number of atoms in reactants(on the left)= total number of atoms in products(on the right)
H₂+O₂---> H₂O
Reactants : H₂, O₂
Products : H₂O
not balanced
H₂O₂ ---> H₂O+O₂
Reactants : H₂O₂
Products : H₂O, O₂
not balanced
Na+O₂ ---> Na₂O
Reactants : Na, O₂
Products : Na₂O
not balanced
N₂+H₂ ---> NH₃
Reactants : N₂, H₂
Products : NH₃
not balanced
P₄+O₂---> P₄O₁₀
Reactants : P₄, O₂
Products : P₄O₁₀
not balanced
Fe+H₂O ----> Fe₃O₄ + H₂
Reactants : Fe, H₂O
Products : Fe₃O₄
not balanced
3. Sulfur
a) Orbital Notation:
OO 0000
DOC
b) Electron Configuration:
4. Iron (Fe)
a) Orbital Notation:
O O OOO OO OO ОО
b) Electron Configuration:
Explanation:
We are to write the orbital notation and electronic configuration of sulfur and iron.
The orbital notation shows the filling of electrons into orbitals or sublevels.
Electron configuration shows the distribution of electrons into shells;
Number of electrons Electron configuration Orbital notation
S 16 2 8 6 1s² 2s² 2p⁶ 3s² 3p⁴
Fe 26 2, 8, 14 2 1s² 2s² 2p⁶ 3s² 3p⁶3d⁶4s²
A sample of CO2 weighing 86.34g contains how many molecules?
Answer:
1.181 × 10²⁴ molecules CO₂
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
86.34 g CO₂
Step 2: Identify Conversion
Avogadro's Number
Molar Mass of C - 12.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of CO₂ - 12.01 + 2(16.00) = 44.01 g/mol
Step 3: Convert
[tex]86.34 \ g \ CO_2(\frac{1 \ mol \ CO_2}{44.01 \ g \ CO_2} )(\frac{6.022 \cdot 10^{23} \ molecules \ CO_2}{1 \ mol \ CO_2} )[/tex] = 1.18141 × 10²⁴ molecules CO₂
Step 4: Check
We are given 4 sig figs. Follow sig fig rules and round.
1.18141 × 10²⁴ molecules CO₂ ≈ 1.181 × 10²⁴ molecules CO₂
Air that has been removed from a bell jar will NOT allow _____________ waves to travel through the jar. Question 4 options: sound light water
Answer:
Sound.
Explanation:
Sound requires a medium such as air to travel.
An independent variable is....
A: What we measure
B: What we change
C: What stays the same
D: What we conclude
Answer:
B - What we change
Explanation:
Dependent Variable - What we measure
Control Variable - what stays the same
Conclusion - what we conclude
Hope this can Help!
:D
will give brainliest if answered correctly
Subject is SCIENCE
Answer:
Gram
Centi-
Centimeter
Kilogram
Decimeter
Liter
Decimal System
Kilo-
Kilometer
Area
Which of the following is an indication of a physical change?
O A. The formation of a new substance
O B. Giving off a smell
O C. A change in the shape of a substance
O D. The production of gas and heat
Answer:
A change in the shape of a substance
Explanation:
Because when ths shape of a sunstance changes , its physical appearance changes .A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
01:44:12
Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state
compare with the temperature at the end of the change?
Temperature vs. Time
140
4
100
80
Temperature (°C)
3
30
40
20
2
0
20
Time (min)
The temperature is always lower
The temperature is always the same
The temperature is usually lower
The temperature is usually higher
someone help me please i’ll give brainly
Answer:
b
Explanation:
i looked it up on Google
Which states of matter can form solutions?
A. Gas-liquid
B. Solid-solid
C. Solid-liquid
D. All of the above
Answer:
c
Explanation:
spongebob cheese pants
Answer:
I believe D
Explanation:
im not super sure but I'm pretttyyy sure
Caculate the density of sulfuric acid if 35.4 mL if. The acid weighs 65.14 grams
Answer:
[tex]\boxed {\boxed {\sf d\approx 1.84 \ g/mL}}[/tex]
Explanation:
Density can be calculated by dividing the mass by the volume.
[tex]d=\frac{m}{v}[/tex]
The mass of the sulfuric acid is 65.14 grams. The volume is 35.4 milliliters.
[tex]m= 65.14 \ g \\v= 35.4 \ mL[/tex]
Substitute the values into the formula.
[tex]d=\frac{65.14 \ g}{35.4 \ mL}[/tex]
Divide.
[tex]d=1.84011299 \ g/mL[/tex]
Let's round to the nearest hundredth to make the answer concise.
The 0 in the thousandth place tells us to leave the 4 in the hundredth place.
[tex]d\approx 1.84 \ g/mL[/tex]
The density of sulfuric acid is about 1.84 grams per milliliter.
How many moles of Cl2 are needed in order to produce 100.0 grams of FeCl3 given the following
equation: 2 Fe + 3 Cl2 → 2 FeCl3
B
T
Answer:
0.92moles
Explanation:
Given reaction:
2Fe + 3Cl₂ → 2FeCl₃
Mass of FeCl₃ = 100g
Unknown:
Number of moles of Cl₂ needed = ?
Solution:
To solve this problem, we work from the known specie to the unknown.
From the mass of the FeCl₃ given, we can solve for the number of moles of the unknown.
Number of moles of FeCl₃;Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of FeCl₃ = 56 + 3(35.5) = 162.5g/mol
Number of moles = [tex]\frac{100}{162.5}[/tex] = 0.62mole
From the reaction expression;
2 mole of FeCl₃ is produced from 3 moles of Cl₂
0.62 mole of FeCl₃ will be produced from [tex]\frac{0.62 x 3}{2}[/tex] = 0.92mole
The number of moles of Cl₂ = 0.92moles
What is the term
chemistry
Answer:
Chemistry is the scientific study of the structure of substances, how they react when combined and how they behave under different situations.
Answer:
The branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances.
Explanation:
Hope this helps!!!!!!
:)
Select ALL of the following statements that are incorrect.
Solids, liquids, and gases are all able to act as solutes in a solution.
Solids, liquids, and gases are all able to act as solvents in a solution.
Solids are not able to act as a solvent if a gas is the solute.
Gases are not able to act as a solvent if a solid is the solute.
Answer:the 4th one is incorrect,and the 1st one is incorrect hope this helps.
Adsorption is defined as a process in which gas molecules tend to adsorb on the surface of a solid solvent.
Therefore, the statement solids are not able to act as a solvent if a gas is the solute, is false.
On the other hand, gases can also act as a solvent if a solid is the solute.
Explanation:
Adsorption is defined as a process in which gas molecules tend to adsorb on the surface of a solid solvent.
Therefore, the statement solids are not able to act as a solvent if a gas is the solute, is false.
On the other hand, gases can also act as a solvent if a solid is the solute.For example, air present in the surrounding acts as a solvent and solid substances present in the surrounding acts as a solute.
Hence, the statement gases are not able to act as a solvent if a solid is the solute, is false.
Thus, we can conclude that following are the statements which are incorrect.
Solids are not able to act as a solvent if a gas is the solute.
Gases are not able to act as a solvent if a solid is the solute.
Two students made the Lewis dot diagrams of NH3. The diagrams are as shown. Two visual diagrams of an N H three molecule are shown. Student As diagram on the left has nitrogen at the center and connects with each hydrogen atom by an arrow pointing away from the nitrogen, one below, one on the right, and one on the left. There is a pair of dots above the nitrogen atom. Student Bs diagram on the right has nitrogen at the center connecting by a straight line to each hydrogen positioned below, to the left, and to the right of nitrogen. There is a pair of dots above the nitrogen atom. Which student drew the correct Lewis dot diagram? Only Student A Only Student B Both Student A and Student B Neither Student A nor Student B
Answer:
Only Student A
Explanation:
The first thing to consider in the diagrams of student A and B is to be sure that that the diagrams obey the octet rule and represent the written formula of ammonia (NH3). Clearly, only the diagram drawn by student A satisfy the these conditions.
If we look at the both diagrams closely, we will discover that the diagram drawn by student B does not satisfy the octet rule nor the trivalency of nitrogen even though it shows the lone pair of electrons on nitrogen hence it can not be the correct dot electron structure for NH3.
Answer: It is neither A or B
Explanation: I took the test and got this correct. Many people are saying only B, but that is wrong.
( please give brainliest :) )
Construct the chemical formulas for the ionic compounds.
Ionic compounds are formed from metal and non-metal elements
Further explanationThe chemical formula of compounds (especially ionic compounds) can be determined from the charge of each ion.
Determination of the ionic charge of the constituent elements of the compound can be seen from the electron configuration to achieve stability according to the octet rule
The charge of each ion will be crossed in the compound
Aluminum bromide
Al³⁺ + Br⁻ ⇒ AlBr₃
Magnesium bromide
Mg²⁺ + Br⁻ ⇒ MgBr₂
Sodium sulfide
Na⁺ + S²⁻ ⇒ Na₂S
Sodium nitride
Na⁺ + N³⁻ ⇒ Na₃N
Can someone help? Ill give brainliest!
Directions: count each side of the reaction then Circle yes or no if it follows the law of conservation of mass
Answer:
Explanation:
before the reaction you have K=2 and Cl=4
after the reaction K=2 and Cl=2 so it does not follow the law of conservation
K20
Molar Mass (g/mole)
2(39.10) + 16.00 = 94.20 g/mole
Moles
5.85 moles
Mass (grams)
Particles
Answer:
yes
Explanation:
that is the answer
Which of these products was made using a renewable resource?
O A. Paper plate
O B. Aluminum can
O C. Copper pan
O D. Plastic bag
Answer:
paper plate
Explanation:
A renuable source is a source that would replenish in ones lifetime. Trees make paper and grow in the span of a average human life.
1. What part of the human body has the same role as the power source in a computer?
2.What part of the human body has the same role as the keyboard or the mouse on a computer?
Answer:
1. The brain
2. MOUSE / KEYBOARD = HANDS
Explanation:
1.The CPU is like the brain of the body. The CPU controls the computer and is the most important part of a computer; similar to the way the brain controls the human body and is very important. Get it?
2.Both are input devices. They are used to send in instructions and information into and out of the computer.
Hope this helps!
1. Find the number of protons, neutrons, electrons and electronic structure of flourine 919F.
2. Write the chemical formula of following compound.
Magnesium hydroxide
3. Balance the following equation
_H2 + _O2 --------> __H2O
1. ₉¹⁹F
2. Mg(OH)₂
3. 2H₂ + O₂ ⇒ 2H₂O
Further explanation1. Fluorine, atomic number : 9 , mass number = 19
Symbol : ₉¹⁹F
protons=electrons=atomic number = 9
neutrons = mass number - atomic mass
[tex]\tt n=19-9=10[/tex]
Configuration : [He] 2s² 2p⁵
2. Magnesium hydroxide is an ionic compound and is a strong base consisting of 2 ions:
Positive ion: Magnesium: Mg²⁺
negative ion: Hydroxide: OH⁻
The charges of the two are crossed, so that the compound becomes:
Mg(OH)₂
3. Reaction :
H₂ + O₂ --------> H₂O
give coefficient :
aH₂ + bO₂ --------> H₂O
H, left = 2a, right 2⇒2a=2⇒a=1
O, left = 2b, right 1⇒2b=1⇒b=0.5
Reaction becomes :
H₂ + 0.5O₂ --------> H₂O x 2
2H₂ + O₂ --------> 2H₂O
Which best explains why aluminum is a nonrenewable resource?
A)It cannot be quickly replaced.
B)It is expensive to process.
C)It conducts electricity.
D)It is useful to humans.
Answer:
A.) It cannot be quickly replaced.
Explanation:
Aluminum is extremely useful to humans but is semi-difficult to produce. Because of this, your answer will be numero uno. (Or A.)
At the Beltway Outlet store, you buy x computer games for 13$ each and a magazine for 4$. Write an expression in simplest form that represents the total amount of money you spend. Someone please help
Answer:
y = 13x + 4
Explanation:
Given parameters:
number of computer games bought = x
cost of each games = $13
number of a magazine = 1
cost of magazine = $4
Unknown:
Total amount of money spent = ?
Solution:
The total amount spent;
let total amount = y
y = total cost of magazine + total cost of computer games
total cost of magazine =$4
total cost of computer games = 13x
y = 13x + 4
When 0.25 moles of NH3 are produced according to the reaction below, how many moles of H2 must have reacted?
N2 + 3 H2 --> 2 NH3
O 1.5 moles H2
O 0.38 moles H2
O 0.25 moles H2
O 0.17 moles H2
Answer:
Explanation:
by stoichiometry
nNH3/2=nH2/3
0.25/2=nH2/3
nH2=0.25×3/2
nH2=0.375 mol
so its 0.38 mol
Answer:
I have this quiz rn I will try 0.38 if it is right I’ll edit this and say that
Explanation:
Hannah added a silvery white metal to a beaker of cold water and noticed that
gas bubbles were given off and a different substance formed. When she
repeated the activity with hot water she noticed the gas bubbles were released
much more rapidly. Which statement best explains why the reaction occurred
faster in hot water?
A ) Hot water increases the collision rate of the molecules, causing the
reaction to occur faster.
B ) Hot water changes the concentration of the chemicals, causing the
reaction to occur faster.
C ) Hot water increases the surface area of the molecules, causing the reaction
to occur faster.
D ) Hot water changes the chemical composition of the water molecules,
causing the reaction to occur faster.
Answer:
A. Hot water increases the collision rate of the molecules, causing the
reaction to occur faster.
Explanation:
Hot water molecules move faster than cold water molecules.
Help please! A gas occupies 500 mL at 270 mm Hg and 55°C. If the pressure is changed to 1.8 atm and the temperature is
increased to 100°C, what is the new volume? Be sure to show the setup and the final answer and unit.
Show Your Work
Answer:
V₂ = 112.14 mL
Explanation:
Given data:
Initial volume = 500 mL
Initial pressure = 270 mmHg (270/760 =0.355 atm)
Initial temperature = 55 °C (55 +273 = 328 K)
Final temperature = 100°C (100+273 = 373 K)
Final volume = ?
Final pressure = 1.8 atm
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 0.355 atm × 500mL × 373 K / 328 K × 1.8 atm
V₂ = 66207.5 atm .mL. K / 590.4 K.atm
V₂ = 112.14 mL
P and Q are two substances such that the melting point of P and the boiling point of Q are the same. If P is a solid at a certain temperature, what state will Q be in at the same temperature?
Answer:
Explanation:
Firstly, it should be noted that melting and freezing points are the same. Thus, when a substance melts at a certain temperature, it means it can also start freezing/solidifying at that same temperature. That been said, when the substance P is a solid at a certain temperature, the other compound Q will boil at that same temperature and hence will be a gas at that same temperature.
If P is solid, it simply means that Q must still be in the liquid state.
From the question, we can see that, the melting point of P and the boiling point of Q are the same. The melting point of a substance is the temperature at which the solid turns to liquid while the boiling point of a substance is the temperature at which a liquid turns to a gas.
If P is solid, it simply means that Q must still be in the liquid state. It has not yet started boiling since the melting point of P and the boiling point of Q are the same.
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