Write 4,500,000 in scientific notation.
4.5x106
Which of the following is a homogeneous mixture?
A) Oil and water
B) Salt water
C) Sand and iron filings
D) Trail mix
B: salt water
What are valence electrons? How many does the element 1s22s22p63s23p2 have?
Valence electrons are the electrons in the outermost shells. Silicon has 4 valence electrons.
How many electrons will completely fill the 3d subshell?
10 electrons
Which of the following is the correct scientific notation for the number 0.00057?
A. 5.7×103
B. 5.7×10−3
C. 5.7×10−4
D. 5.7×104
C
For each of the following processes, indicate whether it represents a physical change or a chemical change.
a. Boiling water
b. Cutting a piece of paper into smaller pieces
c. Iron rusting when exposed to air
a. Physical Change
b. Physical change
c. Chemical change
An isotope of chlorine is written as 1737Cl.
How many protons does this isotope have?
How many neutrons does this isotope have?
How many electrons does this isotope have?
Protons = 17
Neutrons = 20
Electrons = 17
The element Chlorine (Cl) falls in what group on the periodic table?
7A, halogens
The temperature outside is 25°C. What is the equivalent temperature in Fahrenheit?
77 degrees Fahrenheit
What state of matter is in a fixed state with slow moving particles?
Solids
What orbital does the following image represent?
D orbital
Which of the options below has the same number of neutrons as 52Cr
I. 53Cr
II. 52Mn
III. 51V
IV. 54Fe
III and IV
Based on the following equations, what does x equal?
x−3=y
2y+x=12
6
Which of the following scenarios represent a chemical change? Select all that apply.
a. Baking a cake in an oven
b. Ice melting into liquid water
c. Iron reacting with oxygen to form rust
d. Dissolving sugar in water
e. Burning a piece of paper
a. baking a cake
c. iron reacting with oxygen
d. burning a piece of paper
Arrange the following elements in order of decreasing atomic size.
C, Ge, Pb, Si
Pb, Ge, Si, C
Draw the Lewis symbol for Sulfur. How many valence electrons does S have?

A compound is found to contain 12.01 g of carbon (C), 2.02 g of hydrogen (H), and 15.99 g of oxygen (O).
Calculate the percent composition of oxygen in the compound.
53.27%
What are pure substances? Give examples.
Matter with a fixed or definite composition. Examples include elements (MG, O2) or compounds (H2O)
Which of the following orbital diagrams is correct?
E (last one)
Based on two isotopes, the atomic mass of bromine (Br) is 79.90 amu. What is the percent abundance of the isotope with a mass of 81.92 amu if the other isotope (78.92 amu) has an abundance of 50.69%?
49.31%