This measurement of matter is NOT dependent on the force of gravity.
mass
100
The mass of reactants is 10g. What will be the mass of products after a chemical reaction is carried out?
10g (due to Law of Conservation of Mass)
100
As thermal energy goes into an object, what happens to the particles of the object?
move/vibrate faster
100
An _____________ reaction releases thermal energy into the surroundings.
exothermic
100
Draw a Bohr model for Calcium
Calcium:
atomic number = 20
atomic mass = 40
teacher has correct answer
200
The density of an irregular-shaped object can be measured using this technique. (Include each step that will allow you to find the density)
1. Find the mass of the object.
2. Find the volume of the object based on water displacement.
3. D=M/V
200
A log is 1kg. After it is burned, its ash only is .7kg. Use your knowledge of systems to explain WHY mass appears lower here.
This is an open system. CO2 gas is released and cannot be collected to find the mass. The .3kg didn't disappear, it was just released into the surroundings and cannot be easily measured.
200
Liquids have _______ volume and ________ shape. (definite/indefinite)
definite volume/indefinite shape
200
In this type of reaction, the products have LOWER chemical energy than the reactants and thermal energy is ________ (released/absorbed).
exothermic
thermal energy released
200
The _____________ of an atom determines how it will bond.
valence electrons
300
The effect of gravity on a matter is measured as ________.
weight
300
You take a sip of milk and spit it out because it is sour. When you look at the expiration date, you realize it is old :(. A __________ change has occurred.
chemical
300
Gasses have __________ volume and __________ shape (definite/indefinite.)
indefinite volume/indefinite shape
300
In digestion, complex compounds are broken down into simpler ones. Heat will be __________ (absorbed/released) into the surroundings during this ___________ (endothermic/exothermic) reaction.
Released
Exothermic
300
Carbon dioxide, sodium chloride, water, glucose are all examples of ________________.
H2, O2, N3, and carbon dioxide are all examples of _________.
Metal is used in pot/pans in cooking because it conducts heat well. This is a __________ property.
physical
400
Give an example of a state change where thermal energy leaves and object.
Gas to liquid/solid OR liquid to water
400
For an ENDOTHERMIC reaction.
1. Draw a temperature/time graph for the surroundings
2. Draw an energy/time graph for the chemical energy change during the reaction.
teacher provides answer
400
Give two examples of HOMOGENEOUS mixtures and two examples of HETEROGENEOUS mixtures
homogeneous: air, steel, mineral water
heterogeneous: sand and pebbles, "density tower" of liquids, chicken noodle soup, lucky charms
yes - there are the same number of atoms of each element on each side of the equation
500
What is an example of a state change as thermal energy flows into an object?
liquid to gas
solid to liquid
solid to gas
500
You want to make some tea so you place a pot of water on the stove. As the water changes from liquid to gas a ____________ (endothermic/exothermic) process is happening during this state change.
Endothermic
500
How many valence electrons must an atom have so that it is NOT reactive? (number answers needed here)