CHEMISTRY Flashcards
(50 cards)
1
Q
- What type of mixture has a uniform composition throughout?
a) Heterogeneous mixture
b) Suspension
c) Homogeneous mixture
d) Colloid
A
- c) Homogeneous mixture
2
Q
- What is the Tyndall effect used to detect?
a) Solutions
b) Elements
c) Compounds
d) Colloids
A
- d) Colloids
3
Q
- Which of the following elements has the largest atomic radius?
a) Lithium (Li)
b) Potassium (K)
c) Oxygen (O)
d) Fluorine (F)
A
- b) Potassium (K)
4
Q
- As you move across a period, how does electronegativity change?
a) Increases
b) Decreases
c) Remains the same
d) Randomly fluctuates
A
- a) Increases
5
Q
- What does the law of conservation of mass state?
a) Energy is conserved during a physical change.
b) Mass is lost during a chemical reaction.
c) Mass is conserved in both physical and chemical changes. d) The mass of a mixture changes during separation.
A
- c) Mass is conserved in both physical and chemical changes.
6
Q
- What is an isotope?
a) An atom with a different number of protons
b) An atom with a different number of electrons
c) An atom with a different number of neutrons
d) An atom that has lost or gained electrons
A
- c) An atom with a different number of neutrons
7
Q
- Which element has the lowest electronegativity among the options?
a) Fluorine (F)
b) Oxygen (O)
c) Aluminum (Al)
d) Nitrogen (N)
A
- c) Aluminum (Al)
8
Q
- What is the correct formula for gallium oxide?
a) GaO
b) Ga2O3
c) GaO3
d) Ga3O2
A
- b) Ga2O3
9
Q
- Which of the following is a diatomic molecule?
a) CO2
b) H2
c) H2O
d) NaCl
A
- b) H2
10
Q
- Which group of elements tends to form anions?
a) Metals
b) Noble gases
c) Nonmetals
d) Transition metals
A
- c) Nonmetals
11
Q
- Which of the following is a chemical change?
a) Ice melting
b) Water boiling
c) Iron rusting
d) Salt dissolved in water
A
- c) Iron rusting
12
Q
- Which statement best describes a compound?
a) A substance made of only one type of atom
b) A mixture of elements
c) A substance made of atoms of different elements chemically combined
d) Two or more substances physically mixed
A
- c) A substance made of atoms of different elements chemically combined
13
Q
- Which element is a noble gas?
a) Oxygen
b) Neon
c) Nitrogen
d) Hydrogen
A
- b) Neon
14
Q
- What is the charge on an ion that has 11 protons and 10 electrons?
a) 0
b) +1
c) -1
d) +2
A
- b) +1
15
Q
- Which type of bond involves the sharing of electrons?
a) Ionic
b) Covalent
c) Metallic
d) Hydrogen
A
- b) Covalent
16
Q
- What happens to electrons in an ionic bond?
a) They are shared equally between atoms
b) They are lost by one atom and gained by another
c) They are shared unequally
d) They stay in the nucleus
A
- b) They are lost by one atom and gained by another
17
Q
- Which subatomic particle determines the identity of an element?
a) Electron
b) Neutron
c) Proton
d) Isotope
A
- c) Proton
18
Q
- Which of the following best represents a decomposition reaction?
a) H2 + O2 → H2O
b) AB → A + B
c) A + BC → AC + B
d) CO2 + H2O → C6H12O6
A
- b) AB → A + B
19
Q
- What is the correct name for CO2?
a) Carbon oxide
b) Carbon monoxide
c) Carbon dioxide
d) Dicarbon monoxide
A
- c) Carbon dioxide
20
Q
- What is the main difference between a molecule and a compound?
a) Molecules are only made of metals
b) Compounds are made of atoms of different elements
c) Molecules are mixtures
d) Compounds are physically combined
A
- b) Compounds are made of atoms of different elements
21
Q
- Define the term ‘isotope’ and give one example.
A
- Isotopes are atoms of the same element with different numbers of neutrons. Example: Carbon-12 and Carbon-14.
22
Q
- Explain the difference between homogeneous and heterogeneous mixtures.
A
- Homogeneous mixtures are uniform throughout; heterogeneous mixtures have visibly different parts.
23
Q
- Why are noble gases considered stable?
A
- Noble gases have full outer electron shells, making them stable and unreactive.
24
Q
- Differentiate between synthesis and decomposition reactions.
A
- Synthesis: A + B → AB; Decomposition: AB → A + B.
25
5. List two similarities and two differences between ionic and covalent compound naming.
5. Ionic: metal + nonmetal, use charges; Covalent: nonmetals, use prefixes. Both involve naming elements and writing formulas.
26
6. Give two examples of physical and chemical changes.
6. Physical: melting ice, boiling water. Chemical: rusting, burning.
27
7. How do you determine the number of valence electrons using the periodic table?
7. The number of valence electrons equals the group number for main group elements.
28
8. How can you determine whether an atom forms a cation or anion?
8. Metals lose electrons (cations); nonmetals gain electrons (anions).
29
9. Describe the trend of atomic radius across a period and down a group.
9. Across a period: decreases; down a group: increases, due to added energy levels.
30
10. Why is the atomic mass on the periodic table usually not a whole number?
10. Because they are weighted averages of all isotopes of that element.
31
1. The ____________ is the central part of an atom that contains protons and neutrons.
1. nucleus
32
2. The mass number is the total number of ____________ and ____________ in an atom.
2. protons and neutrons
33
3. An atom becomes positively charged when it ____________ electrons.
3. loses
34
4. Isotopes of the same element differ in their number of ____________.
4. neutrons
35
5. As you move down a group, atomic radius _______ because _________.
5. increases; more energy levels
36
6. As you move across a period, atomic radius __________ due to __________.
6. decreases; increased nuclear charge
37
7. Electronegativity is a measure of ________.
7. the ability of an atom to attract electrons
38
8. Electron affinity is the energy _________ when an atom gains an electron.
8. released
39
9. Ionization energy __________ across a period and __________ down a group.
9. increases; decreases
40
10. The periodic table is arranged based on an element’s __________ and __________ properties.
10. atomic number and chemical
41
1. Calculate the molar mass of Ca(NO3)2.
1. Ca(NO3)2 = 40.08 + (14.01 + 3*16.00)*2 = 164.10 g/mol
42
2. Balance the equation: Al + O2 → Al2O3.
2. 4Al + 3O2 → 2Al2O3
43
3. Determine the number of protons, neutrons, and electrons in Mg.
3. Mg: 12 protons, 12 neutrons, 12 electrons
44
4. Draw the full electron shell diagram for phosphorus.
4. Phosphorus: 2, 8, 5
45
5. Use the criss-cross method to write the formula for Al3+ and S2−.
5. Al3+ and S2− → Al2S3
46
6. Calculate the total mass of CH4 + 2O2 → CO2 + 2H2O using atomic masses.
6. CH4 + 2O2 = 16.05 + 2(32.00) = 80.05 g; CO2 + 2H2O = 44.01 + 2(18.02) = 80.05 g
47
7. Write the balanced equation for the formation of Li2O.
7. Li + O → 4Li + O2 → 2Li2O
48
8. Predict the products and state the type of reaction for: Zn + CuSO4 →
8. Zn + CuSO4 → ZnSO4 + Cu (Single Displacement)
49
9. Name the covalent compound: P4O10
9. Tetraphosphorus decoxide
50
10. Explain how ionic bonds form using the terms: electron transfer, ion formation, electrostatic attraction.
10. Electrons are transferred from a metal to a nonmetal forming oppositely charged ions which attract.
