What are tiny particles that make up matter?
a. charges
b. atoms
c. electricity
d. forces
b. atoms
What is the smallest unit of matter?
What happens to the atoms in a reaction?
The following is the equation for sucrose. C12H22O11 Select all that apply to this equation.
What are valence electrons?
How many atoms of Oxygen are in the formula 2H2SO4?
a. 2
b. 4
c. 6
d. 8
d. 8
What is required for a reaction to take place?
Which of the following describes the conservation of mass principle?
Which part of an element is responsible for chemical bonds?
How many protons and neutrons are in this isotope of copper?
a. 63 protons, 29 neutrons
b. 29 protons, 34 neutrons
c. 34 protons, 29 neutrons
d. 29 protons, 63 neutrons
b. 29 protons, 34 neutrons
Which of these are NOT a physical property of matter?
a. density
b. flammability
c. hardness
d. luster
e. reactivity
f. mass
e. reactivity
What are valence electrons?
Which of the following forms of energy is released or absorbed in most chemical reactions?
The diagram shows the formation of water.
Which of the following occurs when water forms?
A Ca2+ ion differs from a Ca atom in that the Ca2+ ion has __________________.
Select all of the below that are properties of water.
a. is a great solute
What type of reaction is this?
a. exothermic
b. endothermic
a. exothermic
Choose the examples that are not examples of chemical reactions.
d. melting a stick of butter
c. element; element; compound
The atomic number is equal to the number of
What do the elements Mg, Ca, and Sr have in common? Select all that apply.
a. They have the same atomic mass.
b. They have the same atomic number
c. They have the same number of valence electrons.
d. They are all in the same group
e. They are all in the same period.
f. Similar chemical and physical properties
c. They have the same number of valence electrons.
d. They are all in the same group
f. Similar chemical and physical properties
What type of reaction is this a picture of?
a. endothermic
b. exothermic
a. endothermic
The following equations represent chemical reactions.
Which of the following is a reactant in the above equations?
A student obtains two strips of magnesium, Mg, ribbon that are each 33 cm long. One strip of magnesium is placed in a test tube containing 55 mL of water, and the other strip is placed in a test tube containing 55 mL of hydrochloric acid, HCl. Both liquids are at room temperature. The student’s observations are recorded in the table.
Which statement is not supported by the student’s observations?
A sulfide anion has a -2 charge because it LOST two valence electrons.