Elements
Elements can be found on the ___________________.
Periodic table
How do you know how many elements are in a compound?
Count the capital letters
What country was Dmitri Mendeleev from?
Russia
If a bike left outside in the rain makes the bike rusty, is it a physical change or chemical change and why?
Rust is a chemical change because the bike cannot be changed back to not being rusty.
Earth's oceans are largely composed of what element?
oxygen
What is the atomic number of hydrogen?
The atomic number is 1.
Compounds are represented as a ___________.
formula
Who was the chemist that formulated the periodic law?
Dmitri Mendeleev
When water freezes to make ice. Is this a physical or chemical change? Explain your answer.
It is a physical change because the water is changing its state of matter; it is changing from a liquid to a solid.
Name 2 of the elements that make up Earth's Living Matter.
potential answers: oxygen, carbon, hydrogen, nitrogen
Elements are a ______________ that cannot be broken down into any other substance.
pure substance
Element or Compound?
Magnesium Sulfate
MgSO4
Compound
What is the name of the weight of an element?
atomic mass
I took a piece of paper and rolled it up into a ball. Is this a physical change or chemical change. Explain your answer.
It is a physical change because a new substance is not formed. It is just changing its shape. There is no new odor, color or other reaction that occurred.
Which of the following is made up of 8% Aluminum?
a) Earth's Crust
b) Earth's Atmosphere
c) Earth's Oceans
d) Earth's Living Matter
a) Earth's Crust
Which substance represented in this equation is classified as an element?
CO -> CO2+H2
a) CO b)H2O c) CO2 d)H2
d) H2
Which one is a compound?
a) oxygen
b) hydrogen
c) glucose
c) glucose
How many periods are there on the periodic table?
7 periods
What are 3 signs that a chemical reaction may have occurred?
-Change in matter (solid, liquid, gas)
-Change in color
-Change of odor
What element occupies 78% of Earth's Atmosphere?
Nitrogen
What element is used as a disinfectant?
Iodine
NaCl is the formula for ____________.
sodium chloride (table salt)
What is the name of the 4th element? (spelling counts)
Beryllium
Is lighting a match a physical or chemical change? Explain your answer.
Lighting a match is a chemical change because there is a new odor, a change of color, and the burnt match cannot be changed back.
What percentage of Earth's Crust is made up of Silicon?
28%