13). Atoms are the basic unit of matter
14). Elements (pure substances, one type of atom) and Compound (made up of two or more types of atoms)
16). Chemical change
17). If a rock is changed or broken and stays where it is, it is weathering. If pieces of pebbles and soil from the rock are moved by natural forces, it is erosion
Hope that helps
Answer:
At the end of 6 hours, 6 feet of the ladder remained above water
Explanation:
we are given the following:
change in tide = 8 inches per hour
1 hour = 8 inches
∴ 6 hours = 8 × 6 = 48 inches
Now, since the length of the ladder is measured in foot, let us convert the rate of tide rising to foot.
12 inches = 1 foot
dividing both sides by 12:
Therefore, after 6 hours, the tide rises by 2 feet.
Next, we are told that the rope ladder at the beginning was 8 feet, hence the length remaining above water after 6 hours of the rising of the tide is calculated as follows:
= 8 feet above water
height of tide = 2 feet = amount submerged in water
∴ length above water = (ladder before rising of the tide) - (amount submerged in water)
length above water = 8 - 2 = 6 feet
Therefore at the end of 6 hours, 6 feet of the ladder remained above water
Answer:
The options are
A) electrical energy.
B) mechanical motion.
C) heat and light energy.
D) electrical and heat energy.
The answer is C) heat and light energy.
Explanation:
Chemical energy in the wood is lit up by fire and a burning process begins to occur. Burning involves a substance being consumed by fire and fire aids in the conversion of some forms of energy to mainly light energy as a result of the burning flames and also to heat energy as a result of the high temperature in the form of heat which the fire brings into play.
This validates the stored chemical energy in the logs being changed into light and heat energy.
The immune system has many kinds of white blood cells to fight infections. HIV finds the white blood cells, called CD4 cells. But with cancer the white blood cells are being killed off.
