U-Science-Gr8-Unit2-PBT-CBT (2020-21) Question: 1-10
Different arrangements of atoms are shown in the figure below.
8
Key
. - hydrogen
O = oxygen
O carbon
8
Figure 1
Figure 3
808
ag
808
OS SO
ag
cs
os
808 308
80
808
as
80
Figure 2
Figure 4
Which figure represents a mixture?
Figure 1
Figure 2
Figure 3
Figure 4

Figure 3

Explanation:

A mixture is a substance made up of two or more different kind of atoms arranged in such a way that they are not chemically linked or joined. This accounts for the reason a mixture can be separated easily. In the figures attached as an image in this question:

- Figure 1 represents an element because it is made up of only hydrogen atoms chemically bonded together to form a molecule.

- Figure 2 represents a compound because it contains hydrogen and carbon atoms chemically joined together.

- Figure 3 represents a MIXTURE because it contains the oxygen and carbon atoms, which are not chemically joined to one another. As seen in the image, the oxygen atoms are not joined to the carbon atoms.

- Figure 4 represents a compound because it contains oxygen and hydrogen atoms chemically bonded together.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation: