The conversion of water into steam is an example of a physical change, where the state of the matter changes without changing its composition. A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.

Correct Option: C

The conversion of water into steam is an example of a physical change, where the state of the matter changes without changing its composition. A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.

By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%.

Correct Option: C

By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%.

Burning coal requires oxygen to chemically react. The availability of oxygen is limited in the furnace by several factors such as the friction of the air against the coal. Blowing provides more oxygen to the flame and raises the temperature of the flame. Besides, it helps to prevent carbon dioxide from forming layer along with dust smoke so as to keep the supply of oxygen intact.

Correct Option: A

Burning coal requires oxygen to chemically react. The availability of oxygen is limited in the furnace by several factors such as the friction of the air against the coal. Blowing provides more oxygen to the flame and raises the temperature of the flame. Besides, it helps to prevent carbon dioxide from forming layer along with dust smoke so as to keep the supply of oxygen intact.

An antacid is a substance which neutralizes stomach acidity. Antacids are taken by mouth to relieve heartburn, the major symptom of gastro-esophageal reflux disease, or acid indigestion which are a few of the common terms used to describe digestive upset.

Correct Option: B

An antacid is a substance which neutralizes stomach acidity. Antacids are taken by mouth to relieve heartburn, the major symptom of gastro-esophageal reflux disease, or acid indigestion which are a few of the common terms used to describe digestive upset.

At birth, there are over 270 bones in an infant body. But many of these fuse together as the child grows, leaving a total of 206 separate bones in a typical adult.

Correct Option: C

At birth, there are over 270 bones in an infant body. But many of these fuse together as the child grows, leaving a total of 206 separate bones in a typical adult.