1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
sergeinik [125]
3 years ago
14

Can anybody help me with this?

Chemistry
1 answer:
asambeis [7]3 years ago
4 0
In many ways, the Rutherford model of the atom is the classic model of the atom, even though it's no longer considered an accurate representation. Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths.

This model of an atom was developed by Ernest Rutherford, a New Zealand native working at the University of Manchester in England in the early 1900s. Rutherford spent most of his academic career researching aspects of radioactivity and, in 1908, won the Nobel Prize for his discoveries related to radioactivity. It was after this that Rutherford began developing his model of the atom.
You might be interested in
You apply the same amount of heat to five grams of water and five grams of aluminum. The temperature of the aluminum increases m
Mashutka [201]
Specific heat is another physical property of matter. All matter has a temperature associated with it. The temperature of matter is a direct measure of the motion of the molecules: The greater the motion the higher the temperature:



Motion requires energy: The more energy matter has the higher temperature it will also have. Typicall this energy is supplied by heat. Heat loss or gain by matter is equivalent energy loss or gain.

With the observation above understood we con now ask the following question: by how much will the temperature of an object increase or decrease by the gain or loss of heat energy? The answer is given by the specific heat (S) of the object. The specific heat of an object is defined in the following way: Take an object of mass m, put in x amount of heat and carefully note the temperature rise, then S is given by



In this definition mass is usually in either grams or kilograms and temperatture is either in kelvin or degres Celcius. Note that the specific heat is "per unit mass". Thus, the specific heat of a gallon of milk is equal to the specific heat of a quart of milk. A related quantity is called the heat capacity (C). of an object. The relation between S and C is C = (mass of obect) x (specific heat of object). A table of some common specific heats and heat capacities is given below:

Some common specific heats and heat capacities: Substance S (J/g 0C) C (J/0C) for 100 g Air 1.01 101 Aluminum 0.902 90.2 Copper 0.385 38.5 Gold 0.129 12.9 Iron 0.450 45.0 Mercury 0.140 14.0 NaCl 0.864 86.4 Ice 2..03 203 Water 4.179 417.9   

Consider the specific heat of copper , 0.385 J/g 0C. What this means is that it takes 0.385 Joules of heat to raise 1 gram of copper 1 degree celcius. Thus, if we take 1 gram of copper at 25 0C and add 1 Joule of heat to it, we will find that the temperature of the copper will have risen to 26 0C. We can then ask: How much heat wil it take to raise by 1 0C 2g of copper?. Clearly the answer is 0.385 J for each gram or 2x0.385 J = 0.770 J. What about a pound of copper? A simple way of dealing with different masses of matter is to dtermine the heat capacity C as defined above. Note that C depends upon the size of the object as opposed to S that does not.

We are not in position to do some calculations with S and C.

Example 1: How much energy does it take to raise the temperature of 50 g of copper by 10 0C?



Example 2: If we add 30 J of heat to 10 g of aluminum, by how much will its temperature increase?

 



Thus, if the initial temperture of the aluminum was 20 0C then after the heat is added the temperature will be 28.3 0C.
5 0
3 years ago
Proteins have two main secondary structures: _______, which are spirals formed by hydrogen bonds between amino acids, and ______
Musya8 [376]

Answer:

Explanation:

Proteins have two main secondary structures: alpha helices, which are spirals formed by hydrogen bonds between amino acids, and beta pleated sheets, [ which are formed by a bend in the amino acid with alternating hydrogen bonding between amino acids.

6 0
2 years ago
A 0.465 g sample of an unknown compound occupies 245 ml at 298 k and 1.22 atm. what is the molar mass of the unknown compound?
nekit [7.7K]
<span>we can find the number of moles of gas using the ideal gas law equation
                                                                                                 
PV = nRT
                                                                                                 
where P - pressure - 1.22 atm
                                               
V - volume - 0.245 L
                                                                                               
n - number of moles
                                                                                               
R - gas constant - 0.08206 L.atm/mol.K
                                               
T - temperature - 298 K
                                                                                               
substituting the values in the equation
                                                   
1.22 atm x 0.245 L = n x 0.08206 L.atm/mol.K x 298 K
                                               
n = 0.0122 mol
                                                                                               
molar mass of compound = mass present / number of moles therefore molar mass = 0.465 g / 0.0122 mol = 38.1 g/mol
the answer is d) 38.0 g/mol </span>
6 0
3 years ago
Read 2 more answers
In an experiment, potassium chlorate decomposed according to the following chemical equation.
Arada [10]

Answer:  

(240 × 3 × 31.998)/(122.5 × 2)   g

Step-by-step explanation:

We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

M_r:          122.5                31.998

               2KClO₃ ⟶ 2KCl + 3O₂

Mass/g:     240  

Mass of O₂ = 240 g KClO₃ × (1 mol KClO₃/122.5 g KClO₃) × (3 mol O₂/2 mol KClO₃)  × (31.998 g O₂/1 mol O₂) = 94.0 g O₂

Mass of O₂= (240 × 3 × 31.998)/(2 × 122.5) = 94.0 g O₂


7 0
3 years ago
Connect and Apply scientific knowledge to explain the following situations:
mixer [17]

Answer:

b.Rearrange the two equations to make each variable the focus (you will end up with three variations for each equation).

7 0
2 years ago
Other questions:
  • Use the drop-down menus to identify each type of sedimentary rock.
    12·2 answers
  • (Chemistry question)
    9·1 answer
  • Which is the least reliable method for identifying a mineral
    5·2 answers
  • A fact of nature that has been confirmed many times by observation is known as a(n).
    15·1 answer
  • 23.6 g of calcium chloride (110.98) is dissolved in water in a calorimeter. T rose from 25.0°C to 38.7°C. Heat capacity of solut
    13·1 answer
  • How did scientist discover that earths outer core is liquid
    9·1 answer
  • Please help me I will give you the brain thing and extra points. 2/9<br> image below
    10·2 answers
  • What is the Sl unit for energy? Be sure to give the full name for the unit
    14·1 answer
  • how much would the boiling point of water increase if 4 mol of NaCl were added to 1 kg of water (Kb=0.51 C/(mol/Kg) for water an
    11·2 answers
  • How does width affect capillary rise?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!