What does matter mean?
Object which has mass and occupies space
What does atom mean?
The smallest particle of a chemical element which is made mainly by 3 sub-atomic particles called Protons,Electrons and Neutrons.
What does molecule mean?
A small group of atoms bonded together.
Answer:
b. independent/manipulated variable
Explanation:
Independent/manipulated variable - refers to the variable that is changed by the scientist or an experimenter. Only one variable that is independent is required to ensure a fair test in an excellent experiment. As the independent variable is being changed by an experimenter or scientist, data is being recorded simultaneously as they are collected.
Answer:
=154.8 J
Explanation:
The rise in temperature is contributed by the change in temperature.
Change in enthalpy = MC∅, where M is the mass of the substance, C is the specific heat capacity and ∅ is the change in temperature.
Change in temperature = 100.0°C-20.0°C=80°C
ΔH=MC∅
The specific heat capacity of gold= 0.129 J/g°C
ΔH= 15.0g×0.129J/g°C×80°C
=154.8 J
In one mole of C7H18 there are 18 moles of H (the number folowing the H)*
>> the ratio is 1:18
In 5.2 moles of C7H18 there are x moles of H
>> the ratio is 5.2:x
Cross multiply the two ratios
1x = 18×5.2
x = 93.6 moles of H
>> In 5.2 moles of C7H18 there are 93.6 moles of H
* This isnt a rule that you can always use.
However to find the mole of a certain element in a certain molucle all you have to do is count how many moles of the element are present in the molecule.
>> example1 >> H2O ;
2 H and 1 O
>> example2 >> CH3COOH ; [you add up all the moles of the same element]
(1+1) 2 C , (3+1) 4 H and (1+1) 2 O
>> example3 >> Mg(OH)2 ; [you multiply whetever is in parenthesis by the number after it 2] 1 Mg , (1×2) 2 O and (1×2) 2 H
Mass is the amount of matter in the body.
Weight is the measure of force.
