If I understand this right, the two elements are Nickel and Copper, elements 28 and 28, respectively. A nickel is worth 5 cents, and a penny, originally comprised of copper, is worth one - the total being six cents.
Answer: Option (D) is the correct answer.
Explanation:
When heat or energy is transferred through the space in the form of waves or through a material medium then it is know as radiation.
For example, when we take Sun bath then our body gets warm due to solar radiation.
For transfer of heat through radiation it is not necessary that the objects have to in contact with each other.
Thus, we can conclude that out of the given options, the transmission of heat without any contact.
Answer:
A chemical change
Explanation:
The marshmallow turning brown and bubbling implies that a chemical change has taken place.
For chemical changes to occur, we observe any of the following:
- a new kind of matter is formed.
- it is always accompanied by energy changes
- the process is not easily reversible
- it involves a change in mass
- requires considerable amount of energy.
ii. Two signs that shows a chemical change has taken place is that:
- bubbles are being formed as it is roasted and it implies that new substances have been formed.
- also, significant amount of heat energy is supplied for the roasting.
D the study of matter, it’s properties, and it’s reactions
Answer:
Explanation:
Mixture: is combination of one or more substances mix together.
• The properties of the mixture are not same and contains the properties of all those component present in it.
• it is a combination of one or more Pure substances and can be separated by simple physical methods.
• it have varying boiling and melting point
Homogeneous Mixture: are those which are not distinguish by naked eye but can be separated into its components by physical means.
The components of a homogeneous mixture are in the same phase oar in dissolved form so it look like one component.
Examples are:
• Salt water is mixture of water and NaCl and can be separated by physical mean.
• Air: mixture of gases
Heterogeneous mixture: are those which can be distinguishing by naked eye and can be separated into its components by physical means.
The component of heterogeneous mixture not fully mixed are different in color or different in phases or not soluble. So one can easily see the difference in the component of the mixture
Examples is
• mixture of salt and sand
• mixture of water and sand
