Topic 1 & 2
What is a chemical property? (Give 3 examples)
Characteristics of a substance that describes its ability to undergo chemical changes or reactions that turn it into a different substance. (e.g.: Reacts with water/air, Reacts with pure oxygen)
What is an element and a compound?
An element is a pure substance made up of only one type of atom, and a compound is a substance formed when 2 or more different types of atoms chemically bond together.
Which two elements are liquid at room temperature?
Mercury, Bromine
What is a proton, neutron, and electron?
proton: positively charged particles
neutrons: neutral/uncharged particles
electrons: negatively charged particles
What are reactants and products?
Reactants are the substances that go into a chemical reaction, and products are the substances produced by the reaction.
1: What does WHMIS stand for?
2: What is the difference between a physical change and a chemical change?
1: Workplace Hazardous Materials Information System.
2: Physical - A substance changes in form but not in chemical composition.
Chemical - Causes one or more new substances to be formed.
What is the law of conservation of mass and the law of definite composition?
Law of conservation of mass: In a chemical change, the total mass of the new substances is always equal to the total mass of the original substances.
Law of definite composition: Compounds are pure substances that contain two or more elements combined together in fixed proportions.
Why are noble gases unreactive?
They have a full electron shell making them stable and not needing to gain/lose any electrons
True or false: A binary compound is a compound made of exactly two different elements.
True, a chemical compound made of exactly two different elements is a binary compound.
E.g NaCl & H₂O
Put this chemical reaction into words: Silver (Ag) + Bromine (Br) --> Silver Bromide
Silver reacts with Bromine to form Silver Bromide
1 - What is the particle model of matter?
2 - What are physical properties? (List 1 qualitative and 1 quantitative example)
1 - All matter is made up of extremely tiny particles, each pure substance has its own kind of particle, particles attract each other, particles are always moving, particles at a higher temperature move faster.
2 - Physical properties are the characteristics of a substance that can be observed without changing the substances chemical identity. (e.g.: color, melting temperature)
What is electrolysis?
The process of breaking down a chemical compound by passing an electric current through it.
What is the difference between mass number, atomic mass, and atomic number
atomic mass: average mass of all the atoms of the element
atomic number: the number of protons in an atom
mass number: the number of protons & neutrons in the atom
State the element symbol, atomic number, and atomic mass of hydrogen.
Element symbol: H
Atomic number: 1
Atomic mass: 1
True or false: Endothermic reactions give off heat while exothermic reaction absorbs heat.
False, endothermic reactions absorb heat, while exothermic reactions give off heat.
What are the types of heterogeneous mixtures?
Ordinary mechanical mixtures: Different parts are big enough to see & stay mixed. Suspensions: Made of large particles that mix but will settle if left alone. Colloids: particles evenly distributed throughout a second substance. Emulsions: Types of colloids where liquids are dispersed in liquids.
What is Dalton's atomic theory?
- All matter is made up of small particles called atoms.
- Atoms cannot be created, destroyed, or divided.
- All atoms of the same element are identical in mass and size.
- Compounds are created when atoms of different elements link together in definite proportions.
What is the difference between a molecule and a compound?
A molecule is formed when two or more atoms bond together chemically, if the atoms are different, the molecule is also a compound, if they are same its not.
What are the seven diatomic molecules?
Hydrogen, Oxygen, Nitrogen, Chlorine, Bromine, Iodine, Fluorine
What are three ways we can prevent corrosion?
Galvanization (applying protective layer of zinc), coating with paint, using other metals as a coating to prevent rust.
1: What are the two types of mixtures?
2: What are the seven observations you can make to know that a chemical change has probably occurred?
1 - Heterogeneous: A mixture where particles are not uniformly scattered.
Homogeneous: A mixture where particles are uniformly scattered.
2 - Heat is produced or absorbed, starting material is used up, change in color, a material w new properties form, gas bubbles in a liquid, a precipitate forms in a liquid, change is difficult to reverse.
What are the four different atomic models?
1. Thomson's Plum pudding model
2. Rutherford's planetary model
3. Bohr's atomic model
4. The electron cloud model
Which 2 families make an easy combination? Why?
alkali metals & halogens
alkali metals have one extra electron they want to lose and halogens need one more electron
What is the difference between alkaline metals, alkali metals, halogens, and noble gases, and what are their groups?
alkali: highly reactive, 1 extra electron (group 1)
alkaline earth metals: reactive but less than alkali, 2 extra electrons (group 2)
halogens: highly reactive, 1 missing electron (group 17)
noble gases: full outer shell, stable (group 18)
Is the following reaction endothermic or exothermic?
2C2H2 + 5O2 ---> 4CO2 + 2H2O + energy
The reaction is exothermic, because the product releases energy (heat)