Acidic solutions have pH of less than 7. Neutral have pH of 7. Basic solutions have pH higher than 7.
A and D seem like the best answers
Answer: The noble gases are a group of chemical elements that make up Group 18 on the periodic table. These gases all have similar properties under standard conditions: they are all odorless, colorless, monatomic gases with very low chemical reactivity.
A star’s life expectancy depends on its mass. Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for about 10 billion years. And if the star is very small, with a mass only a tenth that of the Sun, it can keep fusing hydrogen for up to a trillion years, longer than the current age of the universe.
