Chem test 1

What are the scientific units of measurement?

What are the scientific units of measurement?

For mass, it’s grams. For volume, it’s liters. For length, it’s meters. And for temperature, it’s Celsius.

What tools to find these units of measurement?

Grams are found with a digital scale or triple beam balance, Liters are found with with a graduated cylinder, Meters are found with a meter stick, and temperature is found with a thermometer.

What is matter?

anything that has mass and takes up space

What are some examples of matter?

Light, heat, kinetic and potential energy, and sound are non-matter because they are massless. Objects that have mass and are matter may emit energy. For example, a swinging pendulum consists of matter, but its energy of motion is not matter. This is why most things on earth are matter because they emit energy.

what is mass?

the amount of “stuff” an object has in it.

what is volume?

the amount of space an object takes up

what is density?

The relationship between mass and volume.

how can you find density?

density equals mass divided by volume.

how do you find the density of a cube or any other 3d shapes?

To find the density of a cube or any other regular shape

Step 1- Length X Width X Height

Step 2- Find the mass on a digital scale or triple beam balance

Step 3- Calculate Mass divided by volume.

how do you find the volume of an irregular shape?

To find the volume of an irregular shape you must use the water displacement method developed by Archimedes.

Take a graduated cylinder and measure the volume.

Put your object into the cylinder. The water level will go up. Calculate the new volume.

The volume of your object is the first reading (before you put in the object) minus the second reading (when you put the object in)

what is the meniscus of a graduated cylinder?

the bottom of where the water is in the cylinder, giving you your reading.

what is the density of water?

the density of pure water is just one.

at what density does an object float?

with a density of less than 1, which can be found with a digital scale.

at what density does an object sink?

with a density of more than one, which can be found with a digital scale.

what is buoyant force?

Buoyant Force- Also devised by Archimedes. The idea that an object has a force pushing up and making it float that is equal to the weight of the water it displaces.

The greater the volume= the greater the buoyant force.

what are the 4 phases of matter?

solid, liquid, gas, plasma

what are the shapes and volume of each phase of matter?

Solid- Definite shape, definite volume- particles packed tight and not moving much

Liquid- Indefinite shape, indefinite volume- particles are looser and moving more than solid

Gas- Indefinite shape, indefinite volume- particles are very loose, spreading apart and the particles are moving a lot

Plasma- Indefinite shape and indefinite volume- particles are very loose and spread out. plasma is much hotter than gas, which is why we do not group them together.

how can you go from one phase to the next?

by adding or subtracting heat from the object.

what are non-Newtonian fluids?

when a substance has the properties of a solid and a liquid at the same time.

what is thermal expansion?

The atoms of most substances expand when they are heated and contract when they are made colder. Water is an exception. Water actually expands when it's made colder— Ice expands.

what is sublimation?

the transition of a substance directly from a solid state to a gas state.

what is melting

Melting is the process of changing a substance from a solid state to a liquid state due to an increase in temperature. This occurs when the substance's particles gain enough energy to overcome the forces holding them in a fixed arrangement.

what is freezing

Freezing is the process in which a substance changes from its liquid state to a solid state due to a decrease in temperature. It occurs when the molecules of a substance slow down and arrange themselves in a more ordered pattern, forming a solid structure. The freezing point is the temperature at which this phase transition occurs.

what is evaporation?

a process that turns something from a liquid state to vapor, a gas state. It causes the particles to move more freely and more out of control, which is how the liquid seemingly disappears.

what is condensation?

Condensation is the process by which a gas or vapor changes into a liquid state. It occurs when the temperature of the gas or vapor decreases, causing the particles to slow down and come closer together, forming liquid droplets. This process is commonly observed when warm air cools down and forms water droplets on a cold surface, such as dew on grass or fog on a mirror.

what is an alloy?

An alloy is a mixture of two or more elements, where at least one of them is a metal. It is created by combining the elements through melting, mixing, and solidifying. Alloys often have enhanced properties compared to pure metals, such as increased strength, durability, or resistance to corrosion. Examples of alloys include bronze (copper and tin), steel (iron and carbon), and brass (copper and zinc).

what was the first alloy?

The first alloy created was bronze a mixture of copper and zinc, from the late Neolithic period.

what were Aristotle’s thoughts on the elements?

Aristotle believes that everything is made of earth, air, fire and water. These elements are defined by their possession of one of each of the two fundamental pairs of opposites, hot/cold and wet/dry.

what is an element?

An element is a substance that cannot be broken down into simpler substances by chemical means. It is composed of atoms with the same number of protons in their nuclei. Elements are represented by symbols on the periodic table, such as hydrogen (H) or oxygen (O). Each element has unique properties and characteristics.

who were the alchemists and what were their contributions to chemistry?

The alchemists, who devoted untold grueling hours to transmute metals into gold, believed that in addition to the four Aristotelian elements, two principles gave rise to all natural substances: mercury and sulfur. The progenitor of this theory was the Arabian alchemist Geber.

Why is Marie Curie famous?

Marie Curie is remembered for her discovery of radium and polonium, and her huge contribution to finding treatments for cancer.

why is Antoine Lavoisier famous? What is the Law of the Conservation of Matter?

Antoine-Laurent Lavoisier was a chemist who is known as the father of chemistry. He established the law of conservation of mass, determined that combustion and respiration are caused by chemical reactions with what he named “oxygen,”.

Why is Robert Boyle Famous?

the person who discovered that the volume of a gas decreases with increasing pressure and vice versa—the famous Boyle's law.

Who is Dimitri Mendeleev?

Dmitri Ivanovic Mendeleev was a Russian chemist and inventor. He is best known for formulating the Periodic Law and creating a version of the periodic table of elements.

Why is Albert Einstein Famous?

Albert Einstein is best known for his equation E = mc2, which states that energy and mass (matter) are the same thing, just in different forms.