1.

Question

(03.01 LC)

According to Dalton's atomic theory, which of the following best describes an atom? (5 points)

Can be destroyed

Present in all matter

Composed of elements

Does not contain particles
2.
(03.01 MC)

When positively charged particles were radiated onto a gold atom, most of the particles went straight past. What is most likely the reason for this? (5 points)

Dense area inside the atom

Empty space around the nucleus

Scattered positively charged particles in the atom

Electrons and neutrons inside the nucleus
3.
(03.02 LC)

What is the name of the group of elements that have properties of both metals and nonmetals? (5 points)

Alkaline earth metals

Alkali metals

Metalloids

Noble gases
4.
(03.02 LC)

What elemental trend exists as we move down a column on the periodic table? (5 points)

Chemical reactivity of metals increases

Chemical reactivity of nonmetals increases

Chemical reactivity of metals remains unchanged

Chemical reactivity of nonmetals remains unchanged
5.
(03.02 MC)

A part of the periodic table is shown. (5 points)

A portion of the sixteenth and seventeenth columns of the periodic table is shown. Column 16 reads eight oxygen, 16 sulfur, and 34 selenium. Column 17 reads nine flourine, 17 chlorine, and 35 bromine.

Which of the following elements is less reactive than the others?

Bromine (Br)

Oxygen (O)

Selenium (Se)

Sulfur (S)
6.
(03.02 HC)

Use the portion of the periodic table shown below to answer the questions.

A portion of the first three columns of the periodic table is shown. Column one from top to bottom reads 11 sodium 22.990, 19 potassium 39.098, and 37 rubidium 85.468. Column two reads 12 magnesium 24.305, 20 calcium 40.078, and 38 strontium 87.62. Column three reads 21 scandium 44.956 and 39 yttrium 88.906.

Part 1: Name two elements that have the same properties as sodium (Na). (4 points)
Part 2: Determine the number of protons, electrons, and neutrons present in an atom of calcium (Ca). Explain how you determined your answer using complete sentences. (6 points) (10 points)

7.
(03.04 LC)

What is formed when atoms of one type react with atoms of other types? (5 points)

Compound

Electrons

Element

Protons
8.
(03.04 MC)

Which factor impacts the possible number of ways in which different atoms can be put together? (5 points)

An atom's inability to share neutrons and protons

The ability of atoms to combine in unlimited ways

An atom's inability to react with all elements in the same way

The inability of atoms to share electrons
9.
(03.05 LC)

Which of the following is formed when an acid reacts with a base? (5 points)

Alkaline

Hydrogen ion

Hydroxide ion

Salt
10.
(03.05 MC)

How will the concentration of H+ and OH− ions change when a substance with a pH 11.4 is added to water? (5 points)

Both H+ and OH− will increase

Both H+ and OH− will decrease

H+ will increase and OH− will decrease

H+ will decrease and OH− will increase
11.
(03.05 MC)

Use complete sentences to differentiate between acids and bases on the basis of their behavior when dissolved in water. Give an example of each type. (10 points)

12.
(03.06 LC)

What is a mixture called when it has its different components mixed unevenly within the substance? (5 points)

Heterogeneous mixture

Homogeneous mixture

Impure mixture

Pure mixture
13.
(03.06 LC)

Which of the following methods can be used to separate salt and iron? (5 points)

Distillation

Evaporation

Filtration

Magnetism
14.
(03.06 MC)

Which type of substance can be separated using a centrifuge? (5 points)

A homogeneous mixture with components of same density

A compound with elements of same density

A homogeneous mixture with components of varying density

A compound with elements of varying density

Answer 1

Here are the answers to the questions based on the content provided:

1. Present in all matter - According to Dalton's atomic theory, atoms are the basic units of matter and are present in all types of matter.

2. Empty space around the nucleus - When positively charged particles, like alpha particles, were directed at gold atoms, most passed through because atoms are mostly empty space with a dense nucleus at the center.

3. Metalloids - The group of elements that have properties of both metals and nonmetals is called metalloids.

4. Chemical reactivity of metals increases - As we move down a column (group) of the periodic table, the chemical reactivity of metals tends to increase.

5. Oxygen (O) - Among the listed elements, oxygen is less reactive compared to bromine, sulfur, and selenium because it is located higher in the group of nonmetals.

6. Part 1: Potassium (K) and Rubidium (Rb) - These elements are in the same group (Group 1) as sodium (Na), which means they share similar properties.

   Part 2: Calcium (Ca) has 20 protons, 20 electrons, and 20 neutrons. The number of protons in an atom is equal to its atomic number, which for calcium is 20. The number of electrons equals the number of protons in a neutral atom, and to find the number of neutrons, you subtract the atomic number from the atomic mass (rounded to the nearest whole number, which is 40 for calcium), giving you 20 neutrons (40 - 20 = 20).

7. Compound - When atoms of one type react with atoms of other types, they form compounds.

8. An atom's inability to react with all elements in the same way - This impacts how different atoms can combine to form various compounds.

9. Salt - When an acid reacts with a base, it typically forms a salt and water.

10. H+ will decrease and OH− will increase - Adding a substance with a pH of 11.4 (which is basic) to water will decrease the concentration of H+ ions and increase the concentration of OH− ions.

11. Acids are substances that release hydrogen ions (H+) when dissolved in water, resulting in a solution with a pH less than 7. An example of an acid is hydrochloric acid (HCl). Bases, on the other hand, release hydroxide ions (OH−) when dissolved in water, resulting in a solution with a pH greater than 7. An example of a base is sodium hydroxide (NaOH).

12. Heterogeneous mixture - A mixture with its different components mixed unevenly is referred to as a heterogeneous mixture.

13. Magnetism - To separate salt and iron, magnetism can be used, as iron is magnetic and can be separated from the non-magnetic salt.

14. A homogeneous mixture with components of varying density - A centrifuge can separate components based on density, making it effective for homogeneous mixtures with different densities.

Feel free to ask if you need additional clarification or more information!