2.1 Chemistry in living systems

2.1 Chemistry in living systems

Multiple Select

(Check all that apply)

You...

• have mass

• matter

• have volume

Chemistry is the study of matter

• Matter is anything that has mass and occupies space. (Volume)

• All matter is composed of atoms.

• Atoms are the "building blocks" of the universe

Matter exists in 4 fundamental states (a.k.a. 4 phases)

• solid

• liquid

• gas

• plasma

All matter is either a pure substance or a mixture of substances

(Most everyday items are mixtures)

A pure substance has uniform composition and properties.

• Every portion of a pure substance looks and acts the same

• It can be an element or a compound

An Element

• A substance composed of only one type of atom

• Multiple atoms of the same type can be bonded together.

• Elements cannot be broken down by chemical means.

Multiple Select

Which of the following are elements?

• He

• S₈

• O₃

• O₂

• Fe₂O₃

Multiple Choice

Hydrogen gas, H₂, can be broken down by chemical means.

• True

• False

A Compound

• A substance composed of 2 or more elements chemically bonded.

  
  

• Component elements have a definite ratio (E.g. 2:1 for H:O in water)

• Compounds can be separated by chemical means into their component elements.

  
  

Multiple Choice

Water, H₂O, can be broken down by chemical means.

• True

• False

Multiple Select

Which of the following are mixtures

• tap water

• blood

• beach sand

• bread flour

A Mixture

• A physical combination of 2 or more pure substances

• Component substances can be separated by physical means.

• Component substances retain their original properties.

Recap

• Matter is anything with mass and volume.

• Matter is made of atoms.

• Matter can be pure or a mixture.

• Elements are made of only one type of atom. Cannot be chemically broken down.

• Compounds are made of 2 or more types of atoms. Can be chemically broken down.

Atoms

• All matter is made up of atoms

• The positive parts of an atom are protons

• The center of an atom where its neutrons and protons are is called the nucleus

• An atom with atomic number 6 would have 6 protons

• Particles in an atom that are neutral and have no charge are neutrons

Multiple Choice

True or False? Neutrons have a negative charge

• True

• False

Multiple Choice

What is the atomic number for an element with three protons?

• 6

• 2

• 3

• 1

Chemistry in living systems

• A particle that moves around the nucleus is called an electron

• In the modern periodic table elements are arranged by atomic number

Multiple Choice

What does the 30.974 stand for?

• phosphorus

• atomic mass

• atomic number

• atomic explosion

Multiple Choice

What is the number of protons that the element in this image contain?

• 13

• 32.066

• 8

• 16

Multiple Choice

What are the 3 particles that make-up the atom?

• protons, neutrons, and isotopes

• neutrons, isotopes, and electrons

• positives, negatives, and electrons

• protons, neutrons, and electrons

Atom

• The nucleus of an atom contains protons and neutrons

• different isotopes have different masses

• Isotopes are atoms that have the same number of protons but a different number of neutrons

• The atomic weight represents the weighted average of the isotopes

Poll

How well do you understand atoms, elements, and compounds?

• Very well. I understand it.

• Medium. I may need to study my notes more.

• I do not understand it.

What is a chemical reaction?

• A chemical reaction is a process where a set of substances undergo a chemical change to form a different substance.

Where do chemical reactions occur?

• They happen all the time, every where in the world.

•  Every time you eat, your body uses chemical reactions to break down your food into energy.

• Other examples include metal rusting, wood burning, batteries producing electricity, and photosynthesis in plants.

What are reagents, reactants, and products?

• Reactants and reagents are the substances that are used to bring about the chemical reaction

•  A reactant is any substance that is consumed or used up during the reaction.

• The substance that is produced by a chemical reaction is called the product.

Signs of a Chemical Reaction

• heat production

• change in temperature

• formation of a precipitate

• change in color

• odor production

• light production

• formation of a gas (bubbles)

Multiple Choice

In a chemical reaction

• The atoms of the reactants always stay together to form the products

• The atoms of the reactants unbond, rearrange, and then rebond to form the products

• New atoms are formed which combine to make the products

• Some atoms disappear while others multiply to form the products

  SHOW ANSWER

Multiple Choice

The left side of the equation below is called

• Reactants

• product

Multiple Select

Which observation(s) might be used as evidence that a chemical reaction occurred?

• color change

• odor change

• temperature change

• all of the above

Reaction Rate

• Some happen very quickly like explosions, while others can take a long time, like metal rusting. 

• The reaction rate can be changed by adding energy, a catalyst, or changing the particle size.

• Increasing the concentration or pressure of the reactants can speed up the reaction rate.

Multiple Select

The rate of a chemical reaction is NOT affected by which of the following:

• temperature

• particle size (surface area)

• concentration

• All of these affect rates

Types of Chemical Reactions

• synthesis

• decomposition

• single replacement

• double replacement

• combustion

Assignment

Turn in notes taken from this lesson before leaving class.