Changes in matter
What is the change from liquid to a gas called
Vaporization
paper is cut into pieces
physical
Why is Nitrogen only one Molecule- Explain.
The sign for Nitrogen is N not N^2 so its only one molecule
D= m/v - solve for m
Mutiply V on both sides
When water vapor turns directly into ice. what is this called
Desposition
Is burning wood a chemical change or physical
Chemical
A substance contains two oxygen atoms chemically bonded together. what is its chemical formula
O2
what words are needed to make a Hypothesis
If,then, because
When a solid directly changes to a gas without becoming a liquid, is called?
sublimation
Why is melting Iron a physical change?
Only changes state not the substance
a molecule has 2 hydrogen atoms and 1 oxygen atom. How many total atoms are in the molecule, what substance is it
How to separate Iron and Sand
Use a magnet
Name two signs that a chemical change may have occured
Color, bubbles, temperature, or a new substance
Which change is usually difficult or impossible to reverse using simple physical methods
Chemical change
a student says all molecules are compounds. is the student correct
No, Molecules can contain atoms from just one element, such as O2. Compounds must contain two or more different elements.
D = m/v Solve for V
mutiply M on both sides
Why is density a good property used to identify metals
Its a property that is different for all metals
WHat is the main difference of a Chamical and physical change
A physical change changes the form or state of matter, while a chemical change creates one or more new substance
2 Nitrogen and 3 Oxygen chemically bonded. Is the substance an element, molecule, or compund, or mixture.
Molecule and compund - its particles contain chemically bonded atoms, and those atoms come from two different elements
Explain two types of mixtures
Heterogeneus; easier to see. Homogeneous; harder to see