chapter 1 chem

Observation- gather data

Theory—When we work with the data we gather, we think of a theory in which you take your data and try to make sense of it. Certain order to the analysis process is essential, allowing us to identify patterns and draw meaningful conclusions from our observations. This theoretical framework helps us to formulate hypotheses that can be tested in future experiments, ultimately contributing to a deeper understanding of the phenomena under investigation. In summary, the interplay between observation and theory is crucial, as it guides our analysis and informs the design of subsequent studies. In this way, we can refine our approaches and enhance the validity of our findings, ensuring that our research is robust and reliable.

Law- as a principle that describes the consistent results observed in the gathered data, helping to predict future outcomes based on established patterns. A theory can become law when tested and proven to consistently explain and predict phenomena under specific conditions, thining acceptance within the scientific community. When evidence has been proven to support a theory through rigorous testing and replication, it establishes a strong foundation for its transition into a law, reinforcing its credibility and applicability in various contexts. The theory had repeatedly demonstrated consistent results across multiple experiments, leading researchers to conclude that it could be elevated to the status of a law. This transition not only solidifies the theory's place in the scientific canon but also serves as a guiding framework for future research and applications. Laws allow you to predict what is gonna happen before it happens.

An anomaly is something that does not fit what you are doing. You take the anomaly into account with everything else you were theorizing and you reform the theory. By doing so, scientists can refine their understanding of the underlying principles and ensure that their hypotheses remain robust and adaptable in light of new evidence.

Classification of matter can be understood through various categories, including elements, compounds, and mixtures, each defined by their unique properties and behaviors. Matter is anything that occupies space. We can break down matter into 2 categories

one is a pure substance

2nd is a mixture of things

• Pure substances can be further divided into elements, which consist of only one type of atom, and compounds, which are made up of two or more different types of atoms chemically bonded together.

• Mixtures, on the other hand, can be homogeneous, with a uniform composition throughout, or heterogeneous, with a composition that varies from one region to another.

A pure substance can be an element or a compound.

Element: atoms compounds: connecting atoms H20

Mixture: Homogeneous and heterogeneous mixtures can be separated into their components by physical means, such as filtration or distillation.

Heterogense if you mix two things and they don’t mix, such as oil and water, results in distinct layers that can be easily identified. In contrast, homogeneous mixtures, like salt water, have a uniform composition throughout.

Homogeneous mixture everything mixes and you can’t tell what the components are.

• Solutions: A type of homogeneous mixture where one substance is dissolved in another, resulting in a clear and uniform appearance.

Properties of matter include physical and chemical characteristics that can be observed or measured without changing the substance's identity, such as color, density, melting point, and boiling point.

Physical and chemical properties are essential for understanding the behavior of substances in different conditions and can help predict how they will react with one another.

• Chemical properties, on the other hand, describe a substance's ability to undergo chemical changes, such as reactivity with acids or bases, flammability, and oxidation states. In summary, understanding physical and chemical properties is crucial for predicting the behavior of substances during chemical reactions and their interactions in various environments.

• Mixtures: Combinations of two or more substances where each retains its properties, including heterogeneous mixtures that do not have a uniform composition.

• Physical properties tell what it looks like and can include characteristics such as color, odor, melting point, boiling point, and density. In contrast, chemical properties provide insights into how substances interact at a molecular level, influencing their potential applications in various fields such as materials science, pharmacology, and environmental chemistry.

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Physical and chemical changes refer to the transformations that substances undergo. Physical changes involve alterations in state or appearance without changing the substance's composition, such as melting ice into water or dissolving sugar in water. On the other hand, chemical changes result in new substances with different properties, exemplified by reactions like combustion or rusting. Understanding these differences is crucial for predicting how substances will behave under different conditions and for developing new materials or processes.

Chemical change occurs when you start with one thing and get something new. For instance, when iron reacts with oxygen to form rust, the original iron and oxygen molecules transform to create a completely different substance, demonstrating the importance of recognizing chemical changes in various applications.

SCIENCE knowledge is acquired through systematic observation, experimentation, and analysis, allowing us to understand the principles governing physical and chemical changes.

1. The law of Contradiction states that contradictory statements cannot be true simultaneously. This principle is fundamental in scientific reasoning and helps clarify the distinctions between physical and chemical changes.

   A cannot be A and non-A at the same time. A is whatever we are talking about. For example, if we consider the reaction of baking soda with vinegar, the original substances undergo a chemical change, resulting in the formation of carbon dioxide gas. This is a clear indication that a new product has been created. This illustrates how chemical reactions involve the rearrangement of atoms and the breaking and forming of bonds, leading to new substances with distinct properties.

   Contradictions are impossible

2. Law of causality, every effect has a prior cause. If something is an effect it must have a reason. Every effect has a cause.

3. Reliability of senses This is how we gather data for experiments

The law of contradiction, Law of causality of reliability of senses are the 3 basic laws of science that guide our understanding of the natural world and form the foundation for scientific inquiry.

cause of the universe

1. it created itself for the universe to create itself it must be before it is. It must have existed before it did exist. This paradox challenges our conventional understanding of time and existence, prompting scientists to explore theories such as the Big Bang and quantum mechanics to explain the universe's origins. This is known as the law of contradiction. It is impossible for something to create itself; therefore, the universe's existence raises profound questions about the nature of reality and the limits of human comprehension.

   Spontaneous generation is impossible. This is called Ex nihilo nihil fit which means “out of nothing nothing comes”

2. It was created by something self-existent and eternal. Meaning something else like an outside cause. Turning the universe into existence it has the power to exist in itself. → independent existence self-sufficiency → no cause. This is not a contradiction.

   Point one is asking for nothing to be created and to create something.

3. Aseity means from self

Temp is a measure of how much heat something has

F
C
Kelvin- absolute temp scale

• 0 °C is equivalent to 273.15 K, and this scale is essential in scientific calculations where absolute temperature is required. In addition, the Kelvin scale is crucial for understanding thermodynamic principles, as it allows scientists to calculate energy changes and predict the behavior of gases under varying conditions.

• C and K are related by K=c+273, which means that to convert Celsius to Kelvin, you simply add 273 to the Celsius temperature. Similarly, to convert Kelvin back to Celsius, you subtract 273 from the Kelvin temperature, which provides a straightforward method for switching between these two important temperature scales.

F=1.8C+32 =F, which is the formula for converting Celsius to Fahrenheit. This relationship demonstrates how temperature can be expressed in different units, allowing for flexibility in scientific communication. Understanding these conversions is crucial for accurately interpreting temperature data in various scientific contexts, particularly in chemistry, where precise measurements are essential. 

Scientific notation is another important concept in chemistry. It allows for expressing very large or very small numbers in a compact form, facilitating easier calculations and comparisons. Scientific notation is a way to look at a very large number and a way to look at a very small number.

A large number, for example, 12000000000, is expressed as 1.2 × 10 ^ 9 = 2,000,000,000, which simplifies the representation of quantities such as the number of atoms in a sample. Similarly, a small number like 0.000000005 can be expressed as 5 × 10 ^ -9, making it more manageable for scientific calculations and enhancing clarity in communication. Additionally, scientific notation allows for easier multiplication and division of these quantities, as it simplifies the arithmetic involved and reduces the likelihood of errors when dealing with very large or very small numbers. Another way to write is 1.2E9 is another format for expressing 2 × 10 ^ 9, where 'E' denotes the exponent in scientific notation, commonly used in programming and scientific calculators.

Small number example

0.0000035 can also be expressed as 3.5 × 10 ^ -7, which follows the same principles of scientific notation to facilitate easier computation and understanding. another way 3.5E-7

Temp formulas

F-C (F-32) x 5/9

F-k °F = (K − 273.15) × 1.8 + 32

• C and K are related by K=c+273,

c-f F=1.8C+32 

Measurements

1. length= meter

2. mass= gram

3. volume= liter

base units are meter, gram, and liter

conversion problems

Density is defined as the mass of an object divided by its volume, typically expressed in grams per liter (g/L). Small letter d for density/ When you mix different substances, their densities can change depending on temperature and pressure, which is crucial to consider in various chemical processes. Ice is less dense than water. Most solids are less dense than liquids However, this is not universally true; some solids, like ice, can be less dense than liquids, leading to unique behaviors in mixtures and solutions.

equation for density is d=mass/vol

mass is normally seen in grams

volume could be L or mL

everything you have something cubic is volume 1 cubic centimeter is one mL

1 cc is 1 mL and 1 mL is equivalent to 1 gram of water at standard temperature and pressure. density is a conversion factor

M=dxv

V=m/d

Reliability of measurement and significant figures (sig figs)

sig figs are important in scientific calculations as they indicate the precision of a measurement and help ensure that results are reported consistently. When performing calculations, it is essential to maintain the correct number of significant figures to reflect the precision of the measurements used, which can impact the validity of the final results. For example, when multiplying or dividing measurements, the result should be reported with the same number of significant figures as the measurement with the least number of significant figures.

Rules for determining significant figures include:

• All non-zero digits are always significant.

• Any zeros between significant digits are significant.

• Leading zeros (zeros before the first non-zero digit) are not significant.

• Trailing zeros in a number with a decimal point are significant.

• In scientific notation, all digits in the coefficient are significant. For example, in the number 0.00456, the zeros before the 4 are not significant, while the zeros in 150.0 are significant because they indicate precision.

semi metals metallloids are elements that have properties of both metals and non-metals, such as silicon and germanium, and are often used in the semiconductor industry.

These elements typically exhibit a mix of conductivity, malleability, and ductility, making them essential for various technological applications.

The mole concept is a fundamental principle in chemistry that allows chemists to count particles by weighing them. It defines the amount of substance that contains the same number of entities as there are atoms in 12 grams of carbon-12. Furthermore, the mole provides a bridge between the atomic and macroscopic worlds, enabling chemists to relate the mass of a substance to its number of particles, which is crucial for stoichiometric calculations. In addition to its significance in stoichiometry, the mole concept also plays a vital role in determining concentrations in solutions, allowing for precise calculations in both laboratory and industrial settings. Understanding the mole is essential for mastering chemical reactions and processes, as it facilitates the conversion of mass to moles and vice versa, ensuring accurate measurements and predictions in experiments. The mole thus serves not only as a counting unit but also as a key concept for understanding chemical equations, reaction yields, and the relationships between different substances in a reaction. The practical applications of the mole extend to various areas, including gas laws, where it helps in calculating the volume of gases at standard temperature and pressure, as well as in kinetics, where it aids in understanding reaction rates and mechanisms. Additionally, the mole is instrumental in thermochemistry, where it assists in quantifying heat changes during chemical reactions, thereby providing insights into energy transfer and equilibrium processes. Furthermore, the mole concept is integral in analytical chemistry, where it underpins techniques such as titration and spectroscopy, enabling chemists to determine the concentrations of unknown solutions and analyze the composition of substances. In summary, a thorough grasp of the mole allows chemists to not only perform calculations but also to interpret experimental data and draw meaningful conclusions about the behavior of matter in various chemical contexts. Understanding the mole is therefore essential for students and professionals alike, as it bridges theoretical concepts with practical laboratory skills, enhancing their ability to engage with complex chemical phenomena.