NEW
Font size
Worksheetsscience Grade 8
Total questions: 44
Worksheet time: 22mins
When an atom gains or loses electrons, the charged particle that results is called ( molecule ) .
False /ion
False / polar
True
Which type of substance would best dissolve in a solvent that was made of nonvolatile molecules
A water based slovent
AAn Ionic compound
A solute made of polar molecules
A solute made of no polar molecules
Which can change the solubility of a solid in a liquid
Crushing the solute
Stirring the solute
IIncreasing The pressure
Which ions are present in the greatest amount in a solution whith pH of 8.5 ?
HHydrogen Ions
Hydronium ions
Hydroxide ions
In carbon dioxide, each oxygen atom shares four electrons whith the carbon atom . What is this type of bond called ?
TTriple Covalent
Double covalent
Polar covalent
IIonic
In general , nonmetals are
Good conductors of electricity
Malleable and ductile
GGases At room temperature
Chemical equations are balanced by changing subscript
TTrue
False
According to the law of conservation of mass , three atoms of calcium can react to produce six atoms of calcium
True
False
In an atom , an electron that is close to the nucleus is on the highest energy level
FFalse
TTrue
How many dots are shown in the electron dot diagram for calcium group 2 , element number 20 ?
1
2
20
Substance written to the right of the arrow in a chemical equation is a
Product
RReactent
Catalyst
Metallic compounds
Dissolve in water
Can be hammered into sheets
HHave Low melting point
Energy is needed to break bonds jn chemical reactions
TTrue
False
A chemical reaction in which more energy is absorbed than is released is endothermic
True
False
The ....................... switch places in a double-replacement reaction
Positive ions
Synthesis
Negative ions
Decompose
An ....................... slows or stopes chemical reaction
Inhibitor
Enzyme
Catalyst
IIdk
Which type of reaction requires more activation energy
None of the above
EEndothermic Reaction
Exothermic reaction
TThey Use the same amount of energy
The greatest quantity in the solution is
Solvent
Solute
Acid produce ................. when it dissolve in water
H3O+
OH-
Anathor name for periods is
CColumns
RROWS
Chemical formula =
Symbols + subscripts
CChemical Equation + subscribts
Carboxyl group formula is
-oH
-COOH
-NH2
Amino group formula is
-NH2
-COOH
-OH
The shape of pyramid Is
Planar
Liner
TTetrahedral
This shape is
PPlAner
LLiNer
Proteins are
Not polymers
Nucleotide( from AND, ARN)
Amino Acids( glycine , alanine )
Lipds are
Not polymers
Nucleotide ( from AND,ARN)
Amino acids ( glycine , alanine )
Lipids include
Fats , hormones , waxes , membarans , oil ...
Sugar , starches , and cellulose
Which explains why a soft drink bubbles when the cap is released ?
TThe Gas becomes more soluble when pressure decreases
The gas becomes less soluble when pressure decreases
A...................... can be added to milk to neutralize it
Acid
MMixture
Base
A ........................... uses symbols instead of words to describe a chemical reaction
Chemical equation
Chemical formula
Even exothermic reactions require...........................l.... to start
Energy
Activation energy
A positively charged sodium ion and a negatively charged chlorine ion are joined by a ................................ to form the compound sodium chloride
Covalent bond
Metallic bond
Ionic bond
The nitrogen and hydrogen atoms that make up ammonia are held together by a ............................... because the atoms are both nonmetals
Covalent bond
Ionic bond
Which Group of elements on the periodic table forms covalent compounds whith other nonmetals ?
Group 1
group 2
Group 18
Group 17
Forming a chemical bond
Release energy to the surrounding
Borba energy from the surrounding
The structure of Fullerence is
Sheets
Diamond
Lack arrangement
Cage
What are isomers ?
Compounds that have the same molecular formula but different structural arrangements
Hydrocarbons with only single bonds
Polar molecule
What are substituted hydrocarbons?
Molicule made of small organic molecules
An organic compound in which a carbon atom is bonded to an atom, or group of atoms , other than hydrogen
Has double or triple bonds
Tetrahedral ( a shape of molecule ) is
Methane
Ethane
What is a monomer?
Molecule made up of many small organic molecules covalently bonded together forming a long chain
Molecules that makes purge long chain
Chemical process when small organic molecules or monomer bond together to form a chain?
Synthetic polymers
Polymers
Polymerisation
Monomer
For suffix if the shape is closed what do you put before it ?
Pent
Oct
Non
Cyclo
Acids
(H3O+)=(OH-)
(H3O+)>(OH-)
