chemistry Flashcards
1-8
Define pure chemistry
is the pursuit of chemical knowledge for its own sake.
Define a theory
is a well-tested explanation for a broad set of observations.
List the three steps for solving a mathematical problem:
- analyze (determine where you are starting from), 2. calculate (if you make an effective plan, doing the calculations is usually the easiest part of the process),
- evanulate (after you calculate an answer you should evaluate it, find out if the answer is reasonable and if it makes sense).
Observations
when you use your senses to obtain information
Hypothesis
is a proposed explanation for an observation
Experiment
a procedure that is used to test a hypothesis
Which profession has benefited the most from chemistry?
Medicine, chemistry supplies the medicines, materials, and technology that doctors use to treat their patients.
Organic chemistry
is defined as the study of all chemicals containing carbon
Inorganic chemistry
is the study of chemicals that, in general, do not contain carbon
Biochemistry
the study of processes that take place in organisms
Analytical chemistry
is the area of study that focuses on the composition of matter
Physical chemistry
is the area that deals with the mechanism, the rate, and the energy transfer that occurs when matter undergoes a change.
List 3 pieces of equipment developed by alchemists which are still used today
beakers, flasks, tongs
Which important process did alchemists excel in which is vital today
alchemists developed the tools and techniques for working with chemicals, they designed equipment necessary.
Define scientific law
is a concise statement that summarizes the results of many observations and experiments.
Define a physical change
a change during which some properties of a material change, but the composition of the material does not change.
How do chemical symbols make life in chemistry better?
It helps show what happens to the composition of matter during a chemical change, chemists use chemical symbols to represent elements, and chemical formulas to represent compounds.
Mixture
is a physical blend of two or more components
Substance
is matter that has a uniform and definite composition
Homogeneous mixture
is a mixture in which the composition is uniform throughout.
Heterogeneous mixture
is a mixture in which the composition is not uniform throughout
Define an element
is the simplest form of matter that has a unique set of properties.
Define an extensive property
is a property that depends on the amount of matter in a sample.
Chemical change
is a change that produces matter with a different composition than the original matter.
Physical change
when some properties of a material change, but the composition of the material does not change, (can be classified a s reversible or irreversible)
What do subscripts in a chemical formula indicate?
H2O indicates that there are H+H+O
Accuracy
is a measure of how close a measurement comes to the actual or true value of whatever is measured.
Precision
is a measure of how close a series of measurements are to one another.
What is the SI unit of measurement for length?
The 5 SI base units commonly used by chemists are the meter, the kilogram, the kelvin, the second, and the mole.
Place the following prefixes into order from smallest to greatest:
Pico, nano, micro, milli, centi, kilo
What is the charge and density of an atom’s nucleus like?
the nucleus of an atom is filled with protons and electrons, a proton is positive and an electron is negative. A neutral atom contains equal numbers of protons and electrons. The nucleus occupies most of the atom’s volume but contains little of its mass.
Two isotopes of an element have different numbers of.._______.. And the same number of.._______
..neutrons and different mass numbers.. ..protons and electrons..
All atoms of the same element have the same number of….
Protons but not neutrons.
What did Rutherford’s gold foil experiment demonstrate?
It suggested a new theory of the atom. He proposed that the atom is mostly empty space, thus explaining the lack of deflection of most of the alpha particles. He concluded that all the positive charge and almost all the mass are concentrated in a small region that has enough positive charge to account for the great deflection of some of the alpha particles. He called this region the nucleus.
How is the number of neutrons in an atom calculated?
have to subtract the number of protons from the mass number.
Who is credited with the first idea of atoms?
Democritus, who came up with the idea of indivisible atoms.
What does the mass number of an element equal?
The number of protons in the nucleus of the atom is equal to the atomic number. The number of electrons in a neutral atom is equal to the number of protons.
Dalton theorized atoms are not divisible. Is this still considered true?
No it is false atoms are divisible are are full of smaller particles.
The only way two electron can occupy the same orbit if they have…
Same energy level
What element(s) has four electrons in its 5p sublevel
F, Cl, Br, I
Stable electron configuration generally have what in their outermost level?
Fill putter shell two electrons
What is the outermost configuration for the element selenium?
3s^2 3p^4
Which form of electromagnetic radiation have the highest amount of energy?
Gamma rays
The SI unit hertz measures…
Frequency
The periodic pattern in the physical and chemical properties of elements is evident when they are placed in what order?
Groups
Group A elements are collectively called…
Alkaline metals
For aluminium to become an ion it must lose three electrons from what energy level?
P level
Which subatomic particle plays the greatest role in determining properties?
Electrons
Which period and group has the following highest electron configuration, 5s^2 5p^6
Group 7A and period 2
What sublevel do the transition metals have?
d summer
Which group is the alkali metals?
1A
Why are the noble gases stable?
Filled outer shell
List the metalloids
B, Si, Ge, As, Sb, Te, At
What happens to electronegativity
Left to right-Increases
Down-Decreases
Atomic size
Left to right-Decreases
Down- Increases
Ionic size
Left to right- Decreases
Down-Increases
All the elements in a group have the same number of…
Valence Electrons
Which group has five valence electrons?
5A
The ion antimonide has the same electron configuration as…
Xeon
The nonmetals in Groups 5A-7A become ions by…
Gaining electrons
What is the electron configuration of a chloride ion?
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6
How many valence electrons does an ion of indium have?
3
How do metals react to become more stable
Lose electrons
Why do nonmetals generally gain electrons instead of losing them?
Because the outer shells are almost filled
What is a molecular compound made of?
Molecules
Diatomic molecule: covalent bond holds it together and how many unshared electrons pair
Fluorine- single bond, 6 unshared Chlorine- single bond, 6 unshared Bromine- single bond, 6 unshared Iodine- single bond, 6 unshared Hydrogen- single band, none Nitrogen- triple bond, 2 unshared Oxygen- inadequate
When fluorine combines with sulfur, what gas configuration will fluorine achieve?
Neon
How does a covalent bond form?
Atoms share electrons to achieve noble gas configuration
