10th Grade Chemistry | Unit 1 | Practice Questions & Answers | 2026-2027
physical property Properties that can be determined without altering the chemical makeup of the
material:
hardness, density, color and odor, ability to undergo physical change like boiling,
melting, bending, etc
Influence how a material is used
physical change material remains the same even though its form appears to have changed, such as
the tearing of a piece of paper
chemical change When a substance changes into 1 or more new substances
NOTE COMBUSTION IS A CHEMICAL CHANGE
chemical property relates to the kind of chemical change it can have and also determine its usefulness
eg iron rusting is a chemical change
Can often be observed by a change in state (formation of gas or solid), a permanent
color change, or a temperature change which indicates thermal energy has been
absorbed or given off
particulate level level of atoms and molecules
matter anything that occupies space and has mass
atom the smallest item in a chemical reaction that stays the same; building blocks of all
matter
element matter made up of only 1 kind of atom
CAN NOT BE BROKEN DOWN INTO ANY SIMPLER SUBSTANCES
compound A substance composed of 2 or more elements linked together chemically in a
certain fixed proportion
smallest unit is a molecule
MORE THAN 30 MILLION IDENTIFIED TO DATE
substance each element and compound because each has a uniform and definite composition
as well as distinct properties
molecule a collection of atoms that move and act together as a single entity;
the smallest unit of a molecular compound
atoms are held together by chemical bonds
chemical symbols letters in chemistry that represent atoms, elements and compounds
, 10th Grade Chemistry | Unit 1 | Practice Questions & Answers | 2026-2027
metal include some elements like iron, tin, zinc, and copper
1. HAVE LUSTER
2. ARE MELLEABLE CAN BE HAMMERED INTO SHEETS) 3.CONDUCT
ELECTRICITY
4. OFTEN REACT WITH ACIDS
5. MANY ALSO REACTI WITH COPPER (ii) CHLORIDE
nonmetal include some elements like carbon and oxygen
1.USUALLY DULL IN APPEARANCE
2 ARE BRITTLE
3 DO NOT CONDUCT ELECTRICITY
metalloid elements that have properties intermediate to metals and nonmetals
silicon
germanium
How to calculate density DENSITY = MASS/VOLUME
how to calculate volume of a rectangular prism (box) VOLUME = LENGTH X WIDTH X HEIGHT
how to calculate volume of a cylinder VOLUME = PI X R^2 X HEIGHT
how to calculate volume of a sphere VOLUME = 4/3 X PI X R^3
how do you know if an object will float or sink in a liquid compare the densities of the object and the liquid
The more dense will be at the bottom
how do you know whether a chemical change occurred or observe changes
not 1. new compound formed
2. change of color
Symbol for : hydrogen, carbon, nitrogen, oxygen, and small open circle, small shaded circle, small striped circle, large open circle, large
chlorine spotted circle
Periodic table a chart with elements with similar properties near one another
Atomic number number of protons (which also equals the number of electrons)
Mass number the total number of protons and neutrons in the nucleus of an atom
Isotope atoms with the same number of protons but different numbers of neutrons
(atoms of the same element but with different mass numbers)
physical property Properties that can be determined without altering the chemical makeup of the
material:
hardness, density, color and odor, ability to undergo physical change like boiling,
melting, bending, etc
Influence how a material is used
physical change material remains the same even though its form appears to have changed, such as
the tearing of a piece of paper
chemical change When a substance changes into 1 or more new substances
NOTE COMBUSTION IS A CHEMICAL CHANGE
chemical property relates to the kind of chemical change it can have and also determine its usefulness
eg iron rusting is a chemical change
Can often be observed by a change in state (formation of gas or solid), a permanent
color change, or a temperature change which indicates thermal energy has been
absorbed or given off
particulate level level of atoms and molecules
matter anything that occupies space and has mass
atom the smallest item in a chemical reaction that stays the same; building blocks of all
matter
element matter made up of only 1 kind of atom
CAN NOT BE BROKEN DOWN INTO ANY SIMPLER SUBSTANCES
compound A substance composed of 2 or more elements linked together chemically in a
certain fixed proportion
smallest unit is a molecule
MORE THAN 30 MILLION IDENTIFIED TO DATE
substance each element and compound because each has a uniform and definite composition
as well as distinct properties
molecule a collection of atoms that move and act together as a single entity;
the smallest unit of a molecular compound
atoms are held together by chemical bonds
chemical symbols letters in chemistry that represent atoms, elements and compounds
, 10th Grade Chemistry | Unit 1 | Practice Questions & Answers | 2026-2027
metal include some elements like iron, tin, zinc, and copper
1. HAVE LUSTER
2. ARE MELLEABLE CAN BE HAMMERED INTO SHEETS) 3.CONDUCT
ELECTRICITY
4. OFTEN REACT WITH ACIDS
5. MANY ALSO REACTI WITH COPPER (ii) CHLORIDE
nonmetal include some elements like carbon and oxygen
1.USUALLY DULL IN APPEARANCE
2 ARE BRITTLE
3 DO NOT CONDUCT ELECTRICITY
metalloid elements that have properties intermediate to metals and nonmetals
silicon
germanium
How to calculate density DENSITY = MASS/VOLUME
how to calculate volume of a rectangular prism (box) VOLUME = LENGTH X WIDTH X HEIGHT
how to calculate volume of a cylinder VOLUME = PI X R^2 X HEIGHT
how to calculate volume of a sphere VOLUME = 4/3 X PI X R^3
how do you know if an object will float or sink in a liquid compare the densities of the object and the liquid
The more dense will be at the bottom
how do you know whether a chemical change occurred or observe changes
not 1. new compound formed
2. change of color
Symbol for : hydrogen, carbon, nitrogen, oxygen, and small open circle, small shaded circle, small striped circle, large open circle, large
chlorine spotted circle
Periodic table a chart with elements with similar properties near one another
Atomic number number of protons (which also equals the number of electrons)
Mass number the total number of protons and neutrons in the nucleus of an atom
Isotope atoms with the same number of protons but different numbers of neutrons
(atoms of the same element but with different mass numbers)
