A polymer called polycarbonate is used to make lenses for safety goggles. Scientists use safety goggles to protect their eyes from exposure to dangerous materials in the lab. Safety goggles are hard and resistant to chemicals. Which microscopic properties likely make up polycarbonate?
metal layers surrounded by an electron cloud
metal layers surrounded by an electron cloud
crystals with atoms held together by ionic bonds
crystals with atoms held together by ionic bonds
long carbon chains cross-linked by covalent bonds
long carbon chains cross-linked by covalent bonds
large covalently bonded molecules cross-linked by hydrogen bonds
large covalently bonded molecules cross-linked by hydrogen bonds
Which describes a material that can conduct electricity? (1 point)
metal ions with positive charges attracted to each other
metal ions with positive charges attracted to each other
metal ions attracted to free-flowing electrons
metal ions attracted to free-flowing electrons
metal atoms and non-metal atoms with ionic bonds
metal atoms and non-metal atoms with ionic bonds
metal atoms covalently bonded to other metal atoms
Why does adding elements such as carbon to flexible metals make the material stronger? (1 point)
The added atoms can form ionic bonds with each other, which allows the metal atoms to slide back and forth easily.
The added atoms can form ionic bonds with each other, which allows the metal atoms to slide back and forth easily.
The added atoms can form ionic bonds with the metal atoms, which allows the metal atoms to slide back and forth easily.
The added atoms can form ionic bonds with the metal atoms, which allows the metal atoms to slide back and forth easily.
The added atoms can form covalent bonds with the metal atoms, which prevents the metal atoms from sliding back and forth easily.
The added atoms can form covalent bonds with the metal atoms, which prevents the metal atoms from sliding back and forth easily.
The added atoms can form covalent bonds with each other, which prevents the metal atoms from sliding back and forth easily.
A substance is made of positive and negative ions that are strongly attracted to each other. Which type of material is this, and what type of bonds are present? (1 point)
an ionic material with metal-metal bonds
an ionic material with metal-metal bonds
an ionic material with metal-metal bonds
an ionic material with metal-metal bonds
an ionic material with ionic bonds
an ionic material with ionic bonds
a metal with metal-metal bonds
Glass is made of silica, a polymer made of silicon and oxygen. Based on this information, what conclusions can be drawn about the properties of silica? (1 point)
Silica is a flexible polymer that does not have cross-linking between layers.
Silica is a flexible polymer that does not have cross-linking between layers.
Silica is a hard polymer that does not have cross-linking between layers.
Silica is a hard polymer that does not have cross-linking between layers.
Silica consists of ionically bonded atoms because silicon is a metal, and oxygen is a nonmetal.
Silica consists of ionically bonded atoms because silicon is a metal, and oxygen is a nonmetal.
Silica consists of covalently bonded atoms because silicon and oxygen are both nonmetals.
please help
Alright, let's break it down!
For the first question about polycarbonate, the correct answer would be: long carbon chains cross-linked by covalent bonds.
Next, for the material that can conduct electricity, the correct answer would be: metal ions attracted to free-flowing electrons.
Moving on, adding elements such as carbon to flexible metals makes the material stronger because: the added atoms can form covalent bonds with the metal atoms, which prevents the metal atoms from sliding back and forth easily.
Now, the substance made of positive and negative ions that are strongly attracted to each other is: an ionic material with ionic bonds.
And finally, based on the information given, silica is a: hard polymer that does not have cross-linking between layers.
I hope this helps! Let me know if there's anything else I can assist you with.
The correct answers to the questions are as follows:
1. The microscopic properties likely to make up polycarbonate are long carbon chains cross-linked by covalent bonds.
2. A material that can conduct electricity is one with metal ions attracted to free-flowing electrons.
3. Adding elements such as carbon to flexible metals makes the material stronger because the added atoms can form covalent bonds with the metal atoms, which prevents them from sliding back and forth easily.
4. A substance made of positive and negative ions that are strongly attracted to each other is an ionic material with ionic bonds.
5. Based on the information given, the conclusions that can be drawn about the properties of silica are that: Silica consists of covalently bonded atoms because silicon and oxygen are both nonmetals.
For the first question:
To determine the microscopic properties that make up polycarbonate, we need to consider its chemical structure and bonding.
Option 1: "metal layers surrounded by an electron cloud" is not applicable to polycarbonate. Polycarbonate is a type of polymer, which consists of repeating units of smaller molecules.
Option 2: "crystals with atoms held together by ionic bonds" is also not applicable to polycarbonate. Ionic bonds involve the transfer of electrons between metal and non-metal atoms, and polycarbonate does not have this type of bonding.
Option 3: "long carbon chains cross-linked by covalent bonds" is the correct answer. Polycarbonate is a polymer made up of long chains of carbon atoms that are cross-linked by covalent bonds. This structure gives it its unique properties, such as being hard and resistant to chemicals.
Option 4: "large covalently bonded molecules cross-linked by hydrogen bonds" is not applicable to polycarbonate. Polycarbonate does not have hydrogen bonding.
Therefore, the correct answer is: long carbon chains cross-linked by covalent bonds.
For the second question:
To describe a material that can conduct electricity, we need to consider the nature of its bonding.
Option 1: "metal ions with positive charges attracted to each other" is describing a metallic material. Metallic materials have positive metal ions surrounded by a "sea" of delocalized electrons that can move freely, allowing for the conduction of electricity.
Option 2: "metal ions attracted to free-flowing electrons" is also describing a metallic material, where the positive metal ions are attracted to the free-flowing electrons.
Option 3: "metal atoms and non-metal atoms with ionic bonds" is describing an ionic material. While ionic compounds conduct electricity when molten or dissolved in water, in the solid state, they do not conduct electricity.
Option 4: "metal atoms covalently bonded to other metal atoms" is not applicable to conducting electricity. Covalent bonds do not allow for the easy movement of electrons required for conducting electricity.
Therefore, the correct answer is: metal ions with positive charges attracted to each other or metal ions attracted to free-flowing electrons.
For the third question:
Adding elements such as carbon to flexible metals makes the material stronger due to the formation of covalent bonds.
Option 1: "The added atoms can form ionic bonds with each other, which allows the metal atoms to slide back and forth easily." is incorrect because the added atoms are not forming ionic bonds in this case.
Option 2: "The added atoms can form ionic bonds with the metal atoms, which allows the metal atoms to slide back and forth easily." is incorrect for the same reason as option 1.
Option 3: "The added atoms can form covalent bonds with the metal atoms, which prevents the metal atoms from sliding back and forth easily." is also incorrect. Covalent bonds result in stronger bonding and prevent sliding of atoms.
Option 4: "The added atoms can form covalent bonds with each other, which prevents the metal atoms from sliding back and forth easily." is the correct answer. The formation of covalent bonds between the added carbon atoms strengthens the overall structure of the material, making it harder and more resistant to deformation.
For the fourth question:
A substance made of positive and negative ions that are strongly attracted to each other is an ionic material. Ionic materials have ionic bonds, which involve the transfer of electrons from a metal atom to a non-metal atom.
Option 1: "an ionic material with metal-metal bonds" is incorrect because metal-metal bonds would not involve the presence of positive and negative ions.
Option 2: "an ionic material with metal-nonmetal bonds" is incorrect because it incorrectly implies that the ions are bonded to each other.
Option 3: "an ionic material with ionic bonds" is the correct answer. Ionic materials have ions with opposite charges held together by the attraction between the positive and negative charges.
Option 4: "a metal with metal-metal bonds" is not applicable to the given material description.
Therefore, the correct answer is: an ionic material with ionic bonds.
For the last question:
Based on the information given, we can draw the following conclusions about the properties of silica:
Option 1: "Silica is a flexible polymer that does not have cross-linking between layers" is incorrect. Silica is not a flexible polymer but rather a hard material.
Option 2: "Silica is a hard polymer that does not have cross-linking between layers" is incorrect for the same reason as option 1.
Option 3: "Silica consists of ionically bonded atoms because silicon is a metal, and oxygen is a nonmetal" is incorrect. Silicon is not a metal; it is a metalloid. Silica consists of covalent bonds between silicon and oxygen atoms, not ionic bonds.
Option 4: "Silica consists of covalently bonded atoms because silicon and oxygen are both nonmetals" is the correct answer. Silica, or silicon dioxide (SiO2), is composed of covalent bonds between silicon and oxygen atoms. It forms a network structure, which gives it its hardness and other properties.
Therefore, the correct answer is: Silica consists of covalently bonded atoms because silicon and oxygen are both nonmetals.