18. Focal length is a length which lies between

Gallium is a metallic element in Group III. It has similar properties to aluminium.

Liula [17]

Answer:

Gallium has Orthorhombic and forms ionic bonds with metals

Explanation:

The structure of gallium is Orthorhombic and it has a high neutron capture cross section. It is very stable in dry air but oxidizes in moist air. It reacts with oxygen to form Ga2O3. It has a valence of III. Its electronic configuration is

Ar 3d10 4s2 4p1

It is found in the 3A group of periodic table and it mostly forms ionic bonds with metal.

3 0

2 years ago

Is ice melting in a drink a chemical change?

konstantin123 [22]

Nope, it's a physical change. When ice melts it changes into liquid water, it's still water. Changes in which no new substances are formed are physical changes, hence this is a physical change.

6 0

3 years ago

A statement that best describes a solution

PIT_PIT [208]

A solution is usualy a diluted liquid that cleans for example bleach solution.

6 0

2 years ago

Correct name for #10 please

ira [324]

Answer:

CH₃CH(CH₃)CH(C₃H₇)CH₂CH(CH₃)₂:

4-isopropyl-2-methylpentane.

Explanation:

Step One: Draw the structure formula of this compound. Parentheses in the formula indicate substitute groups that are connected to the carbon atom to the left.

For example, the first (CH₃) indicates that the second carbon atom from the left is connected to:

the CH₃- on the left-hand side,
the -CH(C₃H₇)CH₂CH(CH₃)₂ on the right-hand side,
a hydrogen atom, and
an additional CH₃- group that replaced one hydrogen atom.

Each carbon atom in this compound is connected to four other atoms. All bonds between carbon atoms are single bonds.

The C₃H₇ in the second pair of parentheses is the condensed form of CH₃CH₂CH₂-. See the first sketch attached. Groups in parentheses are highlighted.

Step Two: Find the carbon backbone. The backbone of a hydrocarbon is the longest chain of carbon atoms that runs through the compound. See the second sketch attached. The backbone of this compound consists of seven carbon atoms and is highlighted in green. The name for this backbone shall be heptane.

Step Three: Identify and name the substitute groups.

The two substitute groups are circled in blue in the second sketch.

The one on the right -CH₃ is a methyl group.
The one on the left is branched. $\begin{aligned}\text{CH}_3-&\text{CH}-\text{CH}_3\\[-0.5em]&\;|\end{aligned}$ This group can be formed by removing one hydrogen from the central carbon atom in propane. The name for this group is isopropyl.

Step Four: Number the atoms.

Isopropyl shall be placed before methyl. Start from the right end to minimize the index number on all substitute groups. The methyl group is on carbon number two and the isopropyl group on carbon number four. Hence the name:

4-isopropyl-2-methylheptane.

5 0

2 years ago

According to collision theory, the rate of reaction depends on atoms colliding in the correct _________ with enough ________ for

kenny6666 [7]

Answer: orientation , energy , frequency

Explanation:

According to the collision theory , the number of collisions that take place per unit volume of the reaction mixture is called collision frequency. The effective collisions are ones which result into the formation of products.

Effective collisions depends on the following two factors:-

1. Orientation factor: The colliding molecules must have proper orientation at the time of collision to result into formation of products.

2. Energy factor: For collision to be effective, the colliding molecules must have energy more than a particular value called as threshold energy.

4 0

2 years ago