End of Year Ministry Exam (Science) Flashcards
An atom is made up of…
- positively charged protons
- negatively charged electrons
- neutrally charged neutrons
In energy levels, the first shell can hold a maximum of how many electrons?
2 electrons
In energy levels, the second shell can hold a maximum of how many electrons?
8 electrons
In energy levels, the third shell can hold a maximum of how many electrons?
8 electrons
How do you find the number of protons and electrons in an atom?
the atomic number
What is the name of Group 1?
alkali metals
What is the name of Group 2?
alkaline earth metals
What is the name of Group 7?
halogens
What is the name of Group 8?
inert/noble gases
What do elements in the same group have in common?
they all have the same number of valence electrons
What do elements in the same period have in common?
they all have the same number of electron shells
What are ions?
atoms with a positive or negative charge
This is not a question just make sure to remember this…
Giving and taking electrons:
Group 1 - give away 1 (+1)
Group 2 - give away 2 (+2)
Group 3 - give away 3 (+3)
Group 4 - share with other atoms
Group 5 - take 3 (-3)
Group 6 - take 2 (-2)
Group 7 - take 1 (-1)
Group 8 - none (already stable)
REMEMBER ALL ELEMENTS WITHIN A GROUP FORM IONS WITH THE SAME CHARGE
Ions that lose electrons become _______ charged.
positively
Ions that gain electrons become _______ charged.
negatively
What is the formula for ppm?
1 ppm = 1g of solute/1000000g of solution
What is an electrolyte?
A substance that dissociates into ions when dissolved in water, since they create solutions that conduct electricity.
Ex. HCI, NaOH and NaCl
Electrolytes create…
Acidic, basic and salt solutions
Non-electrolytes create…
Molecular solutions
Which of the following solutions is slightly basic?
Sea water (pH 8), Coffee (pH 5.5) or Gastric juice (pH 2)
Sea water
Which of the following solutions has the highest concentration of H+ ions?
Sea water (ph 8), Coffee (pH 5.5) or Gastric juice (pH 2)
Gastric juice
A truck drives down a highway. The truck tips over and highly acidic liquid leaks out. What should they do to neutralize it?
Add base to the spill
Fill in the blank:
HCl + NaOH —> ______ + H2O
NaCl
Fill in the blank:
2HCl + Ca(OH)2 –> ______ + 2H2O
CaCl2
Describe photosynthesis
Green plants with sunlight and water, remove carbon dioxide and use it to make food (sugar, glucose, oxygen)
Reaction: 6CO2 + 6H2O + sun energy —> C6H12O6 + 6O2
Describe cellular respiration
Cells use oxygen and glucose to make energy (ATP), releasing carbon dioxide back into the atmosphere
the reaction is basically the opposite of photosynthesis im too lazy to write the reaction down
Describe combustion
It is when a fire is created. CO2 and H2O always have to be on the product side
Equation: Fuel + Oxygen —> Carbon Dioxide + Water + Heat
Remember the triangle with fuel, heat and oxygen
Oxygen: Oxidizing agent
Heat: Ignition temperature
Describe oxidation
At least one oxygen atom and at least one other element
Reaction: 4Fe + 3O2 —> 2Fe2O3
What is needed in an acid-base neutralization equation?
Acid + Base —> Salt + Water
When two materials are rubbed together, what transfers from one object to another?
Electrons
When two materials are rubbed together the material thats looses electrons becomes…
Positively charged
What is the formula to solve for current?
I = Q/t
If the current of a circuit is 0.5 A, 20C of charge pass a point in the circuit every ______ seconds.
Answer: 40 seconds
What is the formula for Ohm’s law?
I = V/R or V = (I)(R)
What is the current in the circuit with 100V and 200 ohms?
Answer: 0.5 Amperes (A)
What is the voltage of the battery with 5 ohms and 3A?
Answer: 15 Volts (V)