. 1 pt(s). |
Below is a drawing of an oxygen atom. Which of the diagrams could represent a drawing of a molecule of oxygen?
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A. |
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B. |
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C. |
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D. |
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. 1 pt(s). |
Iron is an element. Which of these could be a drawing of two iron atoms? | ||
A. |
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B. |
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C. |
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D. |
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. 1 pt(s). |
Carbon and zinc are elements. Which of the following could be a drawing of a carbon atom and a zinc atom? | ||
A. |
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B. |
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C. |
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D. |
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. 1 pt(s). |
What is used to test for hydrogen gas? | |
A. | pH paper | |
B. | lime water | |
C. | a burning splint | |
D. | a glowing splint |
. 1 pt(s). |
Which process is a physical change? | |
A. | Rusting iron | |
B. | Burning coal | |
C. | Tarnishing silver | |
D. | Melting ice |
. 1 pt(s). |
Because zinc can combine with other substances but cannot be changed into a simpler substance by an ordinary chemical process, zinc is classified as — | |
A. | a compound | |
B. | a mixture | |
C. | an element | |
D. | an acid |
. 1 pt(s). |
A mixture of iron filings and sulphur can easily be separated by — | |
A. | placing the mixture in water | |
B. | performing a chemical reaction | |
C. | heating the mixture | |
D. | using a magnet |
. 1 pt(s). |
Which of these is best classified as a mixture? | |
A. | Carbon dioxide | |
B. | Water | |
C. | Soil | |
D. | Iron |
. 1 pt(s). |
If you break a piece of glass, the shape of the glass changes, but the properties in the fragments remain the same. Which of the following has occurred? | |
A. | A chemical change | |
B. | A temperature change | |
C. | A state change | |
D. | A physical change |
. 1 pt(s). |
A substance made up of two or more elements that have been chemically combined is called — | |
A. | an atom | |
B. | a compound | |
C. | an element | |
D. | a mixture |
. 1 pt(s). |
In an experiment combining vinegar and baking soda, gas is given off. In this chemical reaction, the vinegar and baking soda are — | |
A. | reactants | |
B. | products | |
C. | elements | |
D. | suspensions |