Answer:
Number 3.
Explanation: The sun produces radiation in the car, which then becomes hot because much radiation is coming in, but little goes out.
Explanation:
Alkali metals are the metals which belong to group 1 of the periodic table. As these elements have one valence electron so they are highly reactive in nature.
Some characteristics of metals are as follows.
- Usually metals are hard in nature.
- They have shiny surface.
- Metals are malleable and ductile in nature.
- Metals are good conductors of heat and electricity.
When these metals react with water then it leads to the formation of metal hydrides.
For example,
Thus, we can conclude the following for alkali metals:
a. What is the group number? - Group 1.
Are these metals reactive? - Yes
b. Do these metals occur freely in nature? - No
c. How many electrons are in their outer shell? - 1 valence electron
d. What are the three characteristics of ALL metals?
- Usually metals are hard in nature.
- They have shiny surface.
- Metals are malleable and ductile in nature.
e. Are these metals soft or hard? - Both
f. Name the two most reactive elements in this group? - Lithium And Sodium
g. What happens when they are exposed to water? - They form hydrides.
The outer planets<span> are further away, larger and made up mostly of gas. The </span>inner planets<span> (in order of distance from the sun, closest to furthest) are Mercury, Venus, Earth and Mars. After an asteroid belt comes the </span>outer planets<span>, Jupiter, Saturn, Uranus and Neptune.</span>
Answer:
The answer to your question is below
Explanation:
An endothermic reaction absorbs heat to proceed.
An exothermic reaction releases heat to proceed.
A. When a certain amount of potassium nitrate is dissolved in water, the water temperature drops from 23°C to 18°C. This is an example of an endothermic reaction because of the temperature diminishes.
B. Jack cooks himself a steak. This is an endothermic reaction because the steak does not cook itself it needs heat to be cooked.
C. When cold water is mixed with sulphuric acid, the mixture can rapidly reach the boiling point of water. This is an exothermic reaction because the temperature of water increases, which means that energy is been released.
D. A flare burns up slowly. I think it is an endothermic reaction because it was supply energy to proceed.
Answer:
Matter is the "stuff" that makes up the universe everything that takes up space and has mass is matter.
All matter is made up of atoms, which are in turn made up of protons, neutrons and electrons