SOMEONE, PLEASE HELP ME AND ILL HELP YOU THIS TAKES MY WHOLE GRADE What is a pure substance?

A. a material that cannot be physically separated into its parts
B. a substance that cannot be separated or broken down into simpler substances by chemical means
C. the smallest unit of an element that has the chemical identity of that element
D. an arrangement of all the known elements in order of their atomic number

#2 - TRUE OR FALSE: Smelting is a process that uses heat to separate pure metals from a mixture that also contains other substances.

A. True
B. False

#3 - TRUE OR FALSE: Currently, 200 elements are known.

A. True
B. False

#4 - What is an element?

A. a material that cannot be physically separated into its parts
B. the smallest unit of an element that has the chemical identity of that element
C. a substance that cannot be separated or broken down into simpler substances by chemical means
D. an arrangement of all the known elements in order of their atomic number

#5 - TRUE OR FALSE: Only two elements can have exactly the same set of properties

A. True
B. False

#6 - What is an atom?

A. a substance that cannot be separated or broken down into simpler substances by chemical means
B. an arrangement of all the known elements in order of their atomic number
C. a material that cannot be physically separated into its parts
D. the smallest unit of an element that has the chemical identity of that element

#7 - TRUE OR FALSE: Atoms are so tiny that they cannot be seen with an optical microscope.

A. True
B. False

#8 - TRUE OR FALSE: Gold and silver are both soft metals that react vigorously with water and air.

A. True
B. False

#9 - What is the periodic table?

A. a substance that cannot be separated or broken down into simpler substances by chemical means
B. a material that cannot be physically separated into its parts
C. the smallest unit of an element that has the chemical identity of that element
D. an arrangement of all the known elements in order of their atomic number

#10 - TRUE OR FALSE: The first column of the table contains a group of very reactive metal elements.

A. True
B. False